The centre-back was strongly linked with a move to West Ham earlier in the summer, with a £30million move seemingly moving close to completion, but Maguire ultimately decided against leaving Old Trafford.
Asked about Maguire and McTominay staying at the club, Ten Hag pointed to the fixture list as he emphasised the need for a strong squad to compete across four competitions.
“If you see the schedule, it’s really condensed,” the United boss explained.
“When you see last season, the World Cup, [it was a] crazy season. Last season takes longer, two weeks [longer]. We played the FA Cup final one week longer, we had a short break, a really condensed pre-season again, so we need numbers but also the numbers have to be quality.
“And I think with this squad, we have the depth and we have quality players in. We can be variable, in a variety of systems and we are happy with it. As I said, we are ready to go into the fight.”