The striker was taken off against Burnley at the weekend with a knee injury and is set to miss out on the long trip south to Home Park.
There is a small chance that he could play at Plymouth but Paul Sturrock calls the chances of him playing 'a leap of faith'.
Scottish hitman MacLean will undergo a scan this afternoon but if as expected, he misses out of Saturday's game, Wednesday would only be left with academy striker Luke Boden.
The club have also confirmed that no loan players will be brought in because of budget restrictions.