Maguire was one of United boss Jose Mourinho’s top targets in the summer but failed to secure the backing of his board after Maguire’s asking price ballooned flowing an excellent World Cup for England.
Reports suggest Mourinho will revisit his interest as he looks to arrest an injury crisis in defence and United’s dreadful start to the season.
A new centre-back is said to be his top priority and he could be given as much as £100million to spend once the January transfer window opens.
However, Puel says he is certain Maguire, 25, will stay with the Foxes until the end of the current season at the very least.
“We cannot have guarantees but I think Harry decided this summer to remain with us and play with us for another season,” he said.
“He is happy with us and saw the quality of the team and its ambition.
“Harry is a valuable player for the club and it is important to keep our best players and maintain our ambition this season.
“I think we will not have a problem this winter because we have a good squad with good guys.”
Maguire has previously admitted he would be open to moving when asked if he would consider moving if he had an offer from a club in the Champions League.
”Yes, definitely it would be a difficult one,” he said.
“If you’re not an ambitious footballer, you’re in the wrong game really.
“Everyone wants to play at the top level, everyone wants to play in the biggest tournaments in the world, so obviously the Champions League is one.”
That being said, United are eight points off the top four in the Premier League and could prove a less tempting proposition next summer.
United have also been linked with a swoop on Tottenham for unsettled star Toby Alderweireld.
The Belgian, 29, is yet to agree a new contract and will be available for a knockdown £24.5million next summer because of a clause in his current deal.
Spurs were demanding around £60m when United last showed interest but the two clubs could now come to a compromise that suits them both in January.