Defeat to Exeter City on Saturday left the Whites clinging on to a one-point advantage over Morecambe going into the last game.
Bolton travel to Crawley and will have one eye on the Shrimps, who host Bradford City at home.
Evatt said too many of his players were “hiding” in the second half against Exeter as the visitors overturned a 1-0 lead to continue their own chase for the play-offs.
But the Wanderers boss hopes his dressing room can produce one last response to criticism when they need it the most.
“It’s a concern, of course it is, but we can’t dwell,” he said of the Exeter performance. “We’re going to be disappointed, there’s no two ways about that but we have to dust ourselves down and go again.
“This team has been through adversity this season and answered questions before. We’ve got one more big one to answer on Saturday.”
Asked if there had been any great difference between a draw and defeat in the final stages of the game – which in either case would have meant Bolton needed a result at Crawley on the last weekend – Evatt added: “Not necessarily because I think if we’d have drawn the game it gives us that bit of a cushion if Morecambe draw, but it’s disappointing.
“It’s the chicken and the egg at the end because they’ve put everyone forward including the goalkeeper and left Shaun (Miller) and Doyler (Eoin Doyle) and if we could have just got the ball and broke we’d have probably scored.
“Debriefing is simple, we just didn’t play as well as we can and we had too many below par.
“Their first one was a well-worked goal and we had other moments in the first half that we didn’t take. They were throwing caution to the wind and putting people forward, running forward, and we didn’t cope with it well enough second half and didn’t play well enough with the ball.”
Hundreds of Bolton fans turned up outside the stadium and though there were some unpleasant scenes which are currently being investigated by the police, most supporters gathered calmly and some stayed behind to help clear up the litter left behind by the crowd.
“It was great to see them obviously, providing it’s done in a peaceful and supportive way,” Evatt said. “We’re all disappointed, but hopefully we can get the job done for next week.”