Philippe Clement gave updates on the squad's availability ahead of this weekend's Sky Bet Championship visit to Charlton Athletic.
"Kenny McLean has been training a few times with the squad and he has been the heartbeat of the team for many years as one of the leaders, so it's important he is back in the squad.
"He will be available for the game but after his absence, it will not be 90 minutes.
"For years he has been the player who has decided the tempo of the game and we need other players to lead like this, knowing when to accelerate the game, when to play forwards. Kenny will not play the next 10 years here, so these are important steps the team is taking.
"I expect Papa Amadou Diallo back here in a few weeks too.
"Vlad (Vladan Kovačević) is also back in selection for tomorrow.
"Grimmy (Daniel Grimshaw) did a really good job in the games he played, he didn't have a massive amount of work to do, which shows how well we've done defensively. I have a tough decision to make between two good goalkeepers tomorrow."
Having played his first minutes this season for the Under-21s in their Premier League 2 tie against West Ham last week, Clement said he was pleased for Mirko Topić on his return from injury.
"It's positive that he is getting minutes in his legs and he played the Bristol game Wednesday too with the young guys, so he is doing well for the injury that he had and the amount of time he had out.
"He will need some time to get up to rhythm and that's normal in these circumstances."