The Citizens were expected to complete the deadline-day signing of the Algeria worldwide, who had handed in a transfer request at King Power Stadium in order to push through the move.
A tale of two halves saw Leicester City held to a 1-1 draw by relegation battlers Swansea on Saturday afternoon.
"The boys will welcome Riyad back and he's no doubt one of our best players, said Maguire".
Mahrez emerged as a late target for Pep Guardiola's league leaders in January following an injury to Leroy Sane, with the two clubs entering negotiations as the deadline approached.
However, the Frenchman has stated that the forward will be assessed when 'he has cleared his head'.
Reintegrating Mahrez into the squad will be a challenge for Puel, with reports that Leicester players are unhappy with their team-mate for submitting a transfer request and trying to force a move to City. We can not change the situation - the transfer window is finished. We need to stay united after all this.
"We created lots of chances with quality and good combinations, a good understanding". He plays for Leicester, he gives a lot good things.
Manchester City were extremely busy on Tuesday, signing defender Aymeric Laporte from Athletic Bilbao in a reported £57million deal before bringing in English midfielder Jack Harrison from sister club New York City.
"After, we will see with Riyad when he can come back with us".