Bury sealed their place in League One on Monday by winning at Chesterfield and Wycombe could join them with a win at Gigg Lane.
Foster said: "It is back in our hands and we have two cup-finals now. We have to take each game at a time and get ourselves ready for Bury.
"If we can put in another good performance then they will have to play pretty well to beat us.
"We have to try not to look at the other side and the fact that they are promoted and will they be up for it or care as much?
"We have to put that to one side and focus on what we have to do. Everything is to play for and everything is at stake. We have to go out there and give it our all and hopefully get the job done."
Source: PA
Source: PA