Argentina international Martinez has missed much of the campaign due to a foot injury and sparked fresh fears on Thursday night when he was seen having strapping applied to his foot following his withdrawal in the dramatic victory at Wolves.
But Erik ten Hag insists he was just exerting caution, with Martinez only making his first Premier League start since September.
"It was a precaution," he said.
"I took him off because, actually I had to sub Rasmus [Hojlund] because he was dead with all his running! But then we needed an extra header but, also for Licha, I think he is a long way out.
“We brought Harry [Maguire] on for [an] extra header and Omari Forson for Rasmus."
Ten Hag also says Casemiro’s minutes will be managed as the Dutchman starts to recover key players for the business end of the season, though the Brazilian lines up in midfield on Sunday as Harry Maguire makes his first start since December 12 in place of Raphael Varane.
Victor Lindelof returns from injury to make the bench, though Mason Mount and Tyrell Malacia remain out. Anthony Martial, meanwhile, is a long-term absentee.
Sofyan Amrabat is available and on the bench after Morocco's campaign at the Africa Cup of Nations came to an end.
Manchester United XI: Onana, Dalot, Maguire, Martinez, Shaw, Mainoo, Casemiro, Garnacho, Bruno Fernandes, Rashford, Hojlund
Subs: Bayindir, Lindelof, Amrabat, Eriksen, Diallo, Varane, Antony, McTominay, Forson
Injuries: Mount, Malacia, Martial, Wan-Bissaka
Time and date: 2pm GMT on Sunday 4 February
Venue: Old Trafford
TV channel and live stream: Sky Sports