Collis made his debut as an early substitute against Bury at the weekend and is set to start at Wycombe on Saturday after Chris Dunn needed 14 stitches in a horrendous facial injury.
Collis said: "I'm definitely up for the challenge. If I can get an extended run in the team then I'll be very happy.
"A strong goalkeeper breeds confidence throughout the team and hopefully I can do that.
"I wish Chris all the best, it was quite a nasty gash to the head that he got and we'll need to see how he is but I'm ready to play.
"I know Gary (Johnson) very well, just the same as he knows me, and I'm confident that we can get out of the situation that we're in. The manager was not impressed with our performance on Saturday, as a lot of people weren't, and he told us that in no uncertain terms. We've got to take that all on board and look forward to the game at Wycombe this weekend."
Source: PA
Source: PA