Millwall lost ground after losing to Yeovil Town last Friday but then turned in a superb display against The Posh on Monday night. However, The Lions have slipped up against the likes of Colchester United and Bristol Rovers at The Den - defeats that could prove costly - and Jackett knows that they need to win in the return fixture against Rovers this weekend to keep the pressure on.
"Every game is difficult if you don't apply yourself," he told the News Shopper. "In this league, where we are, if we apply ourselves then we can beat anyone.
"But we only need to lose five or 10 percent of that focus and we could lose to anyone as well. We are definitely capable of going to Bristol Rovers and winning, but if we are not at our best, will we do it? Probably not.
"We have to apply ourselves, make sure we keep our concentration levels high and ensure we get the details which win matches exactly right."