The most significant setback remains Matthijs de Ligt, who has been sidelined for nearly five months with a lower back injury sustained during the 2-1 win over Crystal Palace in November.
The defender has yet to return to full first-team training and remains in rehabilitation, raising fears he could miss the rest of the campaign and even the upcoming World Cup.
Leny Yoro is also unavailable after being ruled out prior to the recent Chelsea fixture, while Patrick Dorgu faces at least ten weeks on the sidelines with a hamstring injury picked up against Arsenal.
"Hopefully it's only [a] small [issue] but he's obviously not ready for tonight," Carrick said before kick-off at Stamford Bridge.
"It's part of football, you know. We've got a pretty good squad, in terms of injuries really. There's Leny, there's Matthijs, who's out for a bit longer, and there's Patrick [Dorgu].
"It's the two suspensions so all of a sudden there's less options at centre-back. We can adapt and we can make the most of it."
These absences, combined with recent suspensions, forced Carrick into a makeshift defensive setup in the 1-0 victory over Chelsea, where Ayden Heaven partnered Noussair Mazraoui at centre-back.
Lisandro Martínez and Harry Maguire were both suspended for that match, although Maguire is set to return for the Brentford encounter.
Michael Carrick praised Manchester United's adaptability and character after a patched-up side secured a crucial 1-0 victory over Chelsea to strengthen their push for Champions League qualification.
Liam Rosenior conceded Chelsea have "a mountain to climb" to reach the Champions League after a 1-0 defeat to Manchester United extended their dismal run and intensified pressure at Stamford Bridge.
Manchester United defended like trojans and survived a flurry of chances to leave Stamford Bridge with an unlikely 1-0 win in the Premier League on Saturday.
Manchester United strengthened their grip on a Champions League place with a hard-fought 1-0 victory over Chelsea at Stamford Bridge, where Matheus Cunha's decisive first-half strike compounded the hosts' growing crisis.
