It was hard also for Riyad and we have to understand all the parts: for me, for the squad, for the player.
Mahrez was desperate to force through a transfer to Manchester City and is not believed to be in the right frame of mind after the deal collapsed.
Puel insists there is a way back for the Algeria global, who played a starring role in Leicester's shock Premier League title triumph two years ago.
Mahrez will not play any part of Leicester's encounter with Swansea City on Saturday afternoon.
A Fox is on the loose in Leicester, with media reports that Riyad Mahrez has not been seen for a second successive day at the club's training ground.
"As a club, we took this decision for the good of Leicester", said Puel. "We will deal with his side and the club, not in public".
"There is perhaps disappointment for Riyad but I think all the players, all the squad will help him to come back". After the transfer window, it is a tough decision for us to manage now.
"For Riyad, he can clear his head and he can come back with us because he is a very big player for us", said Puel. "He is an important player for us, of course", added Puel.
United are as short as 2/15 to win the game on the Sportsbook, so that tells us all we need to know about who is likely to dominate this match. We have to move forward and to have focus on the football.
Mahrez was a key cog in the Leicester machine as the "Fearless Foxes" stormed to the 2015-16 Premier League title.
Now City are the side looking to capture him, and if Coutinho's huge move to Barca is anything to go by then they may need to dig deep to get their man.
Mahrez is unhappy to have missed out on a move to Pep Guardiola's side, and reportedly isn't taking it well.
Mahrez has been missing for four days, including Wednesday night's 2-1 defeat at Everton with sources close to him claiming he's 'depressed'.