Former United captain Keane made the comments following Arsenal's 1-0 win at Old Trafford on Sunday.
But skipper Maguire has rejected the claims. He told Keane there is enough leadership in the squad to bounce back from a disappointing start to the season.
"I haven't seen his comments because especially after a negative result we don't bring the negativity into the place," Maguire said on Tuesday ahead of the Champions League trip to Istanbul Basaksehir.
"We stay positive and I can say for sure that there's a lot of leaders in this squad. I'm the captain and I've got a lot of leadership around me -- staff and players. No, for sure there are a lot of leaders in this squad."
Keane, who was working as a pundit for Sky Sports in the UK, is a former teammate of manager Ole Gunnar Solskjaer and although the Norwegian said he values his former captain's opinion, he was quick to back up Maguire.
"Roy has always been outspoken," said Solskjaer. "I'm very glad we have the players we've got here. We've got different jobs and Roy's job is to give his opinion and I always listen to Roy, but we always move on with a great group of players and I'm sure we'll see a response [from the Arsenal defeat]."
United will maintain their perfect start to the Champions League group stage with victory in Turkey on Wednesday night.
Despite Jesse Lingard being sidelined, Solskjaer is set to travel with a strong squad but hinted he could hand a European debut to goalkeeper Dean Henderson, who has been No.2 to David De Gea this season.
The defender's form has been under the spotlight following his arrest while on holiday in Greece over the summer but the 27-year-old has played down suggestions the incident has impacted his performances.
"My mind is fully focused on football," he said.
"Obviously I had a difficult period in the summer but I'm fully focused and I come into training each day and work as hard as I can. I focus on each day as it comes. I'm focused on improving and taking this club forward."