Luke Shaw was absent from Manchester United's training session on Wednesday, raising concerns about the left-back position ahead of the team's Champions League opener against Sabah on Thursday night. Manager Michael Carrick may be forced to rely on alternative options due to the defender's unavailability.

During the summer transfer window, Manchester United reportedly showed interest in Lewis Hall from Newcastle but did not pursue a deal. The club also rejected the opportunity to sign Rayan Ait-Nouri on loan from Manchester City on deadline day. Shaw, a veteran defender, started every Premier League game last season, and the club's decision not to secure backup has led to speculation about potential issues if he is unavailable.

Shaw was substituted in the 88th minute of Manchester United's 2-2 draw against Everton on Sunday, with Noussair Mazraoui coming on for him. At the time, the change was widely assumed to be tactical. It remains unclear whether Shaw's absence from training is due to an injury.

Mazraoui, who primarily plays right-back, along with fellow right-back Diogo Dalot, are seen as capable of playing on the opposite flank. Additionally, academy product Harry Amass, who was expected to leave the club, has remained. Reports suggest that Carlos Baleba, a new midfield signing expected to be out until October, could also be utilized as an auxiliary left-back.

In a previous press conference on Friday, Carrick addressed the flexibility of his squad. "We've got players that are flexible as well throughout the whole team that can play in different positions as and when and if we need it," Carrick stated. "Patrick [Dorgu] can certainly play left back. It's something he can, we just haven't had to explore that."

Carrick also noted the return of Patrick Dorgu, who had been sidelined by injury for some time. "He actually has been injured unfortunately for some time, played three or four times for us last season. So, you could almost argue he's almost like a new player, you know, to have, and it's almost like a new signing in some ways because he's added so much to the group."