Martínez injury leaves Man Utd short at the back for Como

Update (30 Oct): Martínez missed Como, where De Ligt made his comeback and United lost 4-1. He came back as a second-half substitute in the 3-0 home defeat by Bournemouth and is in the 22-man squad for Chelsea on Saturday. For his current status and everyone else's, see our live Man Utd injury tracker. The original article from 18 October follows.

The Lisandro Martínez injury looks minor on what we've been told, and it still leaves United in a hole for Wednesday. Martínez went off at half-time at Elland Road with a thigh problem, Leny Yoro is banned for the trip to Como and Ayden Heaven missed Leeds through illness. Carrick's new back three is one game old and it may already be out of centre-backs.

What we actually know about the Martínez injury

Not much, and that's not a criticism. "He felt his thigh a little bit," Carrick told reporters after the 1-1 draw, according to talkSPORT. Elsewhere his exit was put down to a tight thigh. Oddly, the club's own site said Carrick gave no update on Martínez during his post-match media duties, so that one line is the whole of the official picture.

Harry Maguire, who played the first half next to him, told BBC Sport afterwards:

"He went off with a knock, fingers crossed, nothing serious. It's a game of moments and goals change games."

And on the week he'd had:

"There has been a lot of noise around the club this week. Lisandro has apologised, and we have moved on from it. I thought he was brilliant today, so credit to him and let's hope it's not a serious injury."

That should put to bed the social-media theory that his half-time exit was round two with Jason Wilcox. It was a thigh. Nobody has given a timescale and we won't guess one. Taking him off a goal up reads like caution to us.

Who's left for Como

Here's the defensive picture as it stands on Sunday night:

• Lisandro Martínez: thigh, doubtful. No timescale given.
• Leny Yoro: suspended. His straight red in Madrid for denying Jonathan David a goalscoring opportunity carries an automatic one-match ban in Europe under UEFA's Article 63.
• Ayden Heaven: ill. "Ayden has been ill so we had to change just a couple of things really. Marcus has been carrying a little bit of something so we're managing him to a point," Carrick told MUTV before kick-off.
• Matthijs de Ligt: on the bench against Atlético and Leeds, unused both times. He hasn't played for United in almost a year, and Carrick has talked about "a little bit of patience" in getting him up to speed.
• Noussair Mazraoui: back from the injury he picked up with Morocco and played the second half at Leeds.
• Harry Maguire: fine, and the only senior centre-back you can write in pen.

Left-back doesn't help. Carrick said Luke Shaw and Kobbie Mainoo were "close-ish, not close enough" for Leeds, and Patrick Dorgu is still out after getting hurt with Denmark. Before Madrid, Carrick called up the youngster Daniel Armer to ease the shortage. We've been banging on about the left-back United never bought for a while. It's now a whole-defence problem.

Why it hurts the back three most

The new shape gave us our best half of the season, as our Leeds report argued. It was a back three out of possession, with Amad and Diogo Dalot back in their Amorim-era wing-back roles, and Maguire said it was worked on during the week to match Leeds up.

The catch is that a back three needs three centre-backs who win headers, and on Sunday it lost one at the break and the cover was a full-back. Six minutes later Mazraoui headed Jayden Bogle's cross behind, then was beaten by Tarik Muharemović at the corner before Dominic Calvert-Lewin scored. Leeds won 25 aerial duels to our 17.

So for Como, Carrick's honest options are two. Keep the three, probably Maguire, De Ligt and Mazraoui, which makes a European away night De Ligt's first game in nearly a year, in a shape Carrick has used once. Or go back to four, with Maguire and whichever of Heaven or De Ligt is ready. Less exciting, but it's the shape they've played since January.

The depth Martínez was shouting about

Which brings us back to Tuesday. The week started with Martínez going after the club's recruitment after the defeat in Madrid. His words:

"I have to control myself a lot. But sometimes it's a reflection of our club at the moment. We did it last season and now we expect more from the top.

"To bring more players, to compete. Other teams bring in many more players. I expect more from everyone… 100 per cent I expected more from our technical director.

"I have to be honest and also the players have to do more but it's just important when you make a strong squad for this type of night."

He said it at the wrong time and in the wrong place, and he's apologised for that. But one red card, one tight thigh and one bout of illness later, United can't name three fit, first-choice centre-backs for a Champions League game in October. Como is exactly "this type of night".

The club seem to know it. United are reportedly looking at new centre-backs as well as left-backs, and there are said to be real doubts over whether Martínez's deal, which expires in the summer with a club option for another year, will be extended. That's for January and the summer. Wednesday isn't.

Go back to four in Como

If the Martínez injury rules him out, Carrick should park the back three for one night. It's a good idea that needs the right bodies, and Yoro's ban only covers Europe, so he's back for Bournemouth on Sunday. Bring the shape back then.

What we don't want is De Ligt's comeback turned into 90 minutes of learning a new system in Italy. Start him in a four next to Maguire if Heaven isn't right, or bring him on with the game settled. If Martínez is fit, keep the three and don't blink.

One more game without a win and this run reaches seven. Carrick can't afford to lose a game to the treatment room as well.