One minute has been proposed as a halfway house, but BBC Sport understands concerns remain about negative impacts.
Manchester United were angered last season when Matthijs de Ligt was forced to leave the field with a cut, and Brentford scored from a corner while he was off the pitch.
The fear is a one-minute absence would make it far more likely a team could concede a goal when down to 10 players.
Thirty seconds already causes frustration among supporters – and unintended consequences of goals conceded could add further pressure on to officials.
There is an acceptance players use supposed injuries as a way of breaking up play, but it is felt extending the time limit could unduly penalise genuinely injured players.
There are a few exceptions.
If the opponent is shown a yellow or red card the injured player does not need to stay off. Goalkeepers are also exempt, while a penalty taker would be able to stay on.
However, Ifab is not expected to pass any resolution to tackle the tactical timeout. This is when a goalkeeper goes down off the ball in order for a coach to get new instructions to the team.
Ifab’s advisory panels have discussed the issue at some length but, so far, there has been no agreement on a solution.
Following the success of the eight-second rule for goalkeepers holding the ball, new countdown measures are set to be approved.
A similar process will be added to goal-kicks and throw-ins, with possession changing to the opposition if it takes too long.
A 10-second limit will also be applied to substituted players – if they do not get off the pitch the replacement will not be allowed to come on.
A team would have to play with 10 players until the next stoppage, and that must be after at least 60 seconds.
Ifab is expected to approve video assistant referee reviews for wrongly awarded second yellow cards and, as a competition opt-in, corners.
The Canadian Premier League is also likely to be granted permission to start trials of Arsene Wenger’s daylight offside.