Midfielder Montgomery, 30, made his Blades debut in 2000 and is the club's longest-serving player, while striker Cresswell, 34, has made more than 100 appearances for the club since arriving initially on loan in September 2009.
"They are top lads, but it's a decision that's had to be made," Wilson told the Sheffield Star. "We've not had any interest in them at the moment, but obviously the window is open until the end of the month.
"The position the club is in isn't easy and we've had to make the decision to nurture the young players."
Wilson added both players have been left out of the side this season as they no longer figure in his plans.