The Foxes are two points from safety ahead of Monday’s crucial visit of Liverpool with time running out to save their Premier League skins.
Captain Tielemans is out of contract in the summer with the club having tried for the last two years to convince him to sign a new deal.
The midfielder is expected to leave on a free transfer but Smith dismissed any suggestions he was not dedicated to keeping the Foxes up.
“I’m completely comfortable with his commitment, I’ve seen nothing but a committed player in and around the training ground and on the pitch,” he said.
“You have to remember our first game against Man City he was coming back from an injury having been out five or six weeks but was committed to play that game to get himself up to speed as quick as he could.
“He’s still playing catch-up a little bit but he’s got qualities that we need in the team.
“I’m very good at reading people and as soon as I met Youri you know that football means a lot to him, the same about Cags (Soyuncu) when I looked him in the eyes and it means a lot to him.”
The Foxes were jeered off at the break in their 5-3 defeat at Fulham on Monday, when they trailed 3-0, but Smith insisted all his squad must handle the criticism.
He said: “I heard the fan reaction at half-time and I understood that but I don’t go off that. Football is about opinions and it always has been, somebody’s favourite player will be somebody else’s not favourite player and that’s football.
“Unfortunately, as players, you have to deal with the opinions of people and that’s their job to deal with that.”
Nottingham Forest and Leeds picked up draws against Chelsea and Newcastle respectively while Everton’s 3-0 defeat to Manchester City means victory over Liverpool will lift the Foxes out of the bottom three.
“I think they (the players) know the position they’re in and they have done since the moment we came in here,” said Smith. “That’s what we reminded them of and the reason why we’re here, to keep us in the Premier League.
“The players are more than aware of that and I think a perception is always different from what I see day to day on the training ground. What I see day to day are a group of players that care.”