The Clarets lie five points outside the top six in eighth place having won four of their last six npower Championship matches.
Throughout the month, the club have insisted top scorer Charlie Austin is not for sale and McCann feels retaining key personnel at Turf Moor is vital.
"I think it's important to keep everyone together if we're going to have a crack at the play-offs," the midfielder told the Lancashire Telegraph.
"There's no point in getting this far and starting to lose some players that are key to the team.
"There are a lot of players who are out of contract who play every week. It would be a blow to lose somebody.
"It's vital to keep them if we're going to have a push for the play-offs."