Well, just a hypotheical scenario, it might be about timing more than the game itself.
Perhaps Corney has already decided that he's probably the wrong man for the job, but has been trying to avoid the cost of sacking him and paying him off by keeping him under embargo, and generally making his job as difficult as possible to do (e.g. lining up his own tansfer targets rather than leaving it to the manager), thus encouraging him to resign.
Robinson has made it clear he isn't going to jump in recent interviews, so Corney has to decide if he's actually going to push him, in a situation where the club are short on the cash to fund such a move. If he leaves it beyond tonight, it doesn't give a new man much time to make his own moves in the transfer window before it closes. Conversely, a win, and a good performance might convince Corney to keep his compensation money in his pocket and stick with Robinson for the rest of the season.