The Red Devils suffered a 2-1 defeat at the hands of Huddersfield Town in their last league tie, while the Welsh club also lost to Leicester City for the scoreline. United's defeat was due to two errors in the first half, which allowed David Wagner's side to score the two goals.
Phil Jones picked up an injury and was replaced by Victor Lindelof in the first half. The latter's mistake allowed Huddersfield to score their second goal. The England international joins Eric Bailly and Marcos Rojo in the list of injured defenders at Old Trafford.
Jose Mourinho has a decision to make whether to start Lindelof alongside Smalling or give a chance to Axel Tuanzebe ahead of the Swedish international. Clement is aware that United lack options in the centre-back positions and wants Swansea to take advantage of the situation on Tuesday.
"We've looked at the Huddersfield game and I've spoken about that with the players. I've told them any team can be vulnerable at any moment, and we've got to make sure we do our bit right," Clement explained, as reported by Sky Sports.
"They can't make massive changes because they've got injury issues. But we know that whoever they put on the pitch they're going to be good."
Meanwhile, Clement has already confirmed Wilfried Bony and Renato Sanches will miss the Carabao Cup clash against United. Roque Mesa, who moved to the Liberty Stadium from Las Palmas, will start against the EFL Cup winners on 24 October.
The Swans manager admitted that his side's balance is "slightly off" after suggesting that he lacks players in the defence.
"I've got the players I have, but the balance is slightly off. We're potentially a little bit heavier in midfield than we would have liked and a little short at the back, particularly at left-back," he said.
"If there is an issue with Martin (Olsson) there, who would be able to step in? You'd be asking a player who's not a natural left-back, or you go down into the next level at your club. But I've just got to get on with it and maybe then we can address some of the balance issues in January."
United have already defeated Swansea 4-0 in the Premier League earlier in August at the Liberty Stadium. The clash saw the Red Devils score three goals in the final quarter of the game.