Some fluff, if nobody minds

In the morally/ethically ambiguous world of BB shady deals is a common affair, be it referees officially allowed to accept bribes, or sponsors threatening your life if they think you weren't endorsing them enough. Though matches' organizers still struggle to preserve a semblance of sportsmanship on the pitch, to not disappoint their audience (and thus not lose their source of income), they don't have enough political power to fend off pressure put by grim reality of intense multiple-layer competition common in this environment.
Thus a new trend has arrived and rooted in, finally getting official approval, the same way as bribes did before. A limited negotiations over course of the ongoing match are now allowed, under strict supervision of the Referee Guild. A completely and blatantly negotiated matches are not (yet?) tolerated, of course, as this would surely divert a lot of fans from the game, thus diminishing profits of a lot of involved.. entities.
Some of those deals are agreed upon and discussed between both coaches in details preemptively, before the match starts (yet so artistically executed, that seem like the real thing.. almost), others are improvised on spot, with an ultimatum thrown in the opposing coach's face while one of his best players is being stomped or stabbed on the pitch in front of him.
The idea itself:
A new optional Extortion/Shady Deals mechanics are added, which deal with new and enhances some old alleys of psychological warfare coaches may confront each other at. In certain clearly defined/regulated circumstances you may try to reach to the opposing coach using a referee as your mediator, proposing him a certain deal he may find.. acceptable, which he cannot violate after agreement is signed (there probably could be some D6 roll involved, and on 6 he still manages to find a loophole in the protocol and get away with it, while Extorting coach still follows his part of the deal). Each coach is granted one Extortion per match for free.
Here are some situations it may be used in:
1. When your opponent's valuable player was severely injured and he doesn't have Apo roll, or couldn't reroll it properly - you may offer him services of your own Apo instead (in case of failed Apo rolls this basically means he got another chance to reroll it with yours).. for a price. Your Apo is consumed, if he agrees. This item differs from the next one in that it covers all possible situations where your opponent could get hurt, like falling on GFI, Dodge or Leap etc, even if it happens during his own turn.
2. When your foul or PO (may be even a regular Blitz/Block/Stab or Wizard/Horatio) action was extremely effective, severely injuring/killing your opponent's valuable player(s), and he couldn't re-roll the injury properly with Apo (or doesn't have it), you may offer him to forget your grudge and revert all harm done to the player.. for a price. If your opponent agrees, the whole situation is perceived as if instead of actually hurting the player you would just threatened his life, extorting the opposing coach. If he submits to your claims, he can get back the Apo he wasted on him and his player is left on the ground in the same state he was in before that final armor/injury roll that led to Extortion (that's probably is too mild, and may doesn't seem like a good deal; probably should be at least left stunned, or moved to KO box, or those could be possible options you can choose when making your offer; in addition, player of the moving team which inflicted this injury he could be allowed to keep all SPPs he earned from it, even if the other coach submits to demands and thus injury is negated); yet your own player who committed the said actions still is left as he was after committing them (lying on the ground if it was PO, or staying adjacent in case of foul/block/Stab). So it's handled as sort of wicked re-roll happened. It probably also could work the same in case of inflicting injury when crowd surfing the player - like if you just threatened you will do this, if opposition won't submit to your claims.
Edit:
3. With your lips curved into a devilish smirk, you challenge your opponent to dare to reject your demands! As you've definitely got an ace up your sleeve! And you are not bluffing, not at all! At any time in the game (or, perhaps, at the start/end of your turn? or at kick off?), you can spend your Extortion to make a demand to your opponent. Draw 6-8 cards from Special Cards deck(s) dealing with some effects changing situation on the pitch and team's state drastically (Random Events, Dirty Tricks, Miscellaneous Mayhem are nice candidates; some artifacts cards may fit as well), without showing them to your opponent; out of them you need to select 2-3 which will be applied to your team, and 2-3 for the opposing team, and must discard the rest, while showing the discarded ones (but not the ones you selected!) to your opponent. You then clearly state which set of cards will be applied to which team. Then you make your demand. It's the other coach who must decide whether the cards will be applied, in the end (he can't know which exactly those cards are until it happens). If he decides it worth the risk, he rejects your demand and the cards are immediately played by the designated teams, whatever it will bring upon them (if card's effect cannot be applied at all, it's discarded; if it may still be able to apply till the end of the drive(half? match?), i.e., there is a slight possibility for it to happen, it's left in pending state, and applied immediately when possible; other approach could be that it's left to both coaches discretion when exactly to apply cards "assigned" to their opponent) Otherwise, he submits to your claims, and cards are discarded (you are allowed to show it to them, though, bragging about how finely you screwed them

The idea here is that you must try to scam/bluff the opposition into actions which will benefit you most. It's as if you prepared some plot to disrupt their game (or may be just trying to look like it will disrupt their game more than yours..), but offer them last time to consider giving you what you want before you'll proceed with your suicidal shenanigans (potentially hurting yourself in the process). The card usually either helps the team it will be applied to, or harms it. You know exactly what it is, and have a chance to make it more harmful for them than for yourself by redistributing the cards (as if you would try to scheme against them), but you can't apply them yourself - you need to trick the opposing coach into doing it for you. The requirement to show them discarded cards is needed for them to have a chance to evaluate credibility of your threats. Like, if they see you're discarding powerful cards, they may think you left even more powerful ones in place. Or may be you're just trying to trick them by discarding the only one valuable card you had, who knows; scaring them to death and making them accept your demand, thus fooling them into actually giving you what you need.
Edit2:
4. You can spend your Extortion action to add +2(+3?+4?) to either Armor or Injury roll during foul action. The opposition may negate it by spending their own Extortion. If it does seem too overpowered, fouler's chances to be caught could also be increased in that case; as an additional deterrent, the opposition could be allowed to not reveal their intentions until the foul is actually committed - then they may (or may not) negate the modifier - while fouler's chances of being caught are still left increased. Then again, it may be too harsh already, so it could be allowed to re-roll either armor, or injury roll, in addition to the bonus?
Thus you sort of provoke the other coach into burning his Extortion, by threatening his player - may benefit you if you have plenty yourself (like, in case optional rule allowing to pay for additional extortions with bribe is active). Or if you are more afraid of him using it for something else. Or may be you just don't care and want to gamble with all you've got to remove some player from the pitch.
If you succeed with the "Extortion foul" with result making you eligible for employing 2) from above, you can proceed with it and handle it like it's an extra free Extortion event of this type (thus, if you already have spent your free Extortion, and used a bribe to conduct the 4), you still is allowed to do 2) for free; if you still have your free Extortion, it's not spent if you decide to follow 4) with 2) as well). This works in such way even if the other coach decides to negate it by spending his Extortion.
Edit3:
5. If you have a ball-carrier in clear (i.e. no rolls of any kind) one-turn range of your opponent's end zone, it's your turn, and you haven't moved him yet, you may opt to make some demand to the other coach, proposing to effectively spoil your scoring opportunity in exchange (you must either release the ball, or throw it in the nearest crowd (coach being extorted chooses), and end your turn immediately). Can only be attempted once per drive, to prevent griefing with it constantly while stalling. This could be used in a lot of subtle ways, ranging from earning some profits from a match which doesn't change situation that much for you (like, you'll be kicked out of tournament in any case, or you think you simply can't win this one match anyway) to playing mind games with your opponent (like, you are sure yourself, that it's nothing and you'll get another chance to score soon anyway, so why not to risk a bit and extort something valuable from him?)
Other situations could be devised as well, I guess. Possible options of what could be demanded are provided in the next post. Additional ideas are highly anticipated

Some limit for number of Extortions could be set to make it harder to abuse this mechanics.. in any way. Once per half/match, per coach should be enough, I guess. In 1) and 2) the Extortion is only considered "spent" if it's resulted in opponent submitting to your claims. In 3) it's always spent.
Edit:
Optional rule: you may spend your bribes to execute additional extortion actions (1 bribe - 1 extortion)
Edit2:
..as additional limitation, they could be categorized, with only types 1), 2) and 5) allowed to be used for free (still once per match), and other 2 are only available for a bribe; bribes still allows you to use "free" kinds of Extortions more than once, as well (i.e., each bribe allows you to use one more Extortion of any kind)