Manchester United are facing a full-blown defensive crisis for Wednesday's crucial Champions League encounter with Serie A outfit Como.

The Red Devils trained on Tuesday morning and will fly to Italy on Tuesday afternoon ahead of the European fixture with Cesc Fabregas' side.

Leny Yoro will definitely miss the match through suspension, having been sent off in the team's 2-0 defeat to Atletico Madrid in the Champions League last week.

Meanwhile, Lisandro Martinez, who was forced off at the interval of Sunday's Premier League clash with Leeds United due to a thigh issue, is a major doubt.

Martinez did not train on Tuesday morning, while the same can also be said for Ayden Heaven, who was absent against Leeds last time out through illness.

Man United have severe defensive issues ahead of Como clash

Patrick Dorgu is again set to miss out with the hamstring injury that he suffered while representing Denmark during the September/October international break.

Luke Shaw was also missing from Tuesday's session, as the Englishman deals with his second injury problem of the campaign.

Matthijs de Ligt is now back in the fold, but the Netherlands international has not played for almost a year due to a chronic back injury.

As a result, Man United head coach Michael Carrick is facing a serious problem when it comes to selecting his defence for Wednesday's clash.

Harry Maguire is a certain starter, and he could be partnered by Noussair Mazraoui in the middle of the back four.

Amass could be in line for surprise start against Como

Mazraoui is a full-back by trade but can feature in the middle of the defence.

Diogo Dalot would then potentially operate at right-back, with Harry Amass or Jaydan Kamason in line to complete the defensive lineup.

Amass has already played in the Champions League this season, featuring against Sabah in the team's first match of the tournament, and the youngster could now be in line for a spectacular start against Como.

Marcus Rashford was also missing from training; the Englishman has been nursing a hip issue this season and could be absent alongside Kobbie Mainoo (unspecified).

Meanwhile, Benjamin Sesko continues to recover from a chronic shin issue, and it is unclear when the striker will be able to return to the field.

Man United head coach Carrick will answer questions on the injury situation during his press conference on Tuesday evening.