Lisandro Martinez's criticism of Manchester United's summer transfer business is being proven right by the unfolding injury crisis at Old Trafford. United are back in Champions League action on Wednesday evening, facing Como away from home in their third league phase fixture.

Michael Carrick's men defeated Sabah in their opening game but lost to Atletico Madrid last week in a game that also saw Leny Yoro sent off late in the game, adding to the availability problems that have arisen after the weekend's draw with Leeds United in the Premier League.

Carrick has come under real pressure amid a disappointing start to the season that has seen his side win just one of their first seven Premier League games.

After last week's defeat to Atletico, defender Martinez called out the club's poor business in the summer, making it clear that he 'expected more' from the club's director of football, Jason Wilcox, in terms of recruitment. United did spend money, but they failed to address key issues like at centre-back, left-back and arguably in the striker positions, all of which are lacking in depth.

The latest injury issues have exposed that lack of depth, with Carrick confirming ahead of the Como clash: "A bit of a mixed bag, we've got quite a few missing. [Martinez] is not that bad, but he is not with us. Kobbie (Mainoo), we're looking at another 10 days or so, and Luke (Shaw) a little bit longer than that.

"We have a bit of illness and injuries. Ayden is ill. Marcus is still feeling a hip issue that we're trying to overcome."

Asked about young left-back Harry Amass, who did well during pre-season, coming into the squad, Carrick added: "Yeah, for sure (he could feature). That is why he's with us, he's right in contention. At some point players need an opportunity."

On the Benjamin Sesko injury, Carrick added: "We're hoping soon that we have a clear picture. I'm not trying to delay it, hopefully by the end of the week we will have something clearer. There has been some work going on."

Man Utd's lack of depth is being exposed

The quality of signings is always going to be up for debate. Fans always want their club to be signing superstars, and be it because of money or where a team currently is in terms of competitiveness, that's not always possible. But for a club like Man Utd to be lacking depth in key positions is inexcusable.

United have injury-prone 32-year-old Luke Shaw as their only natural senior left-back, relying on winger Patrick Dorgu to be the deputy on that side. At he heart of defence, there just isn't enough quality, with Martinez having struggled to stay fit, Harry Maguire struggling to keep up with the pace at 33 years of age and with Yoro still unproven, even with some good signs.

Man Utd's summer signings

Then, up top, there is Benjamin Sesko and little else, given United would probably likely to have offloaded the struggling Joshua Zirzkee, while Matheus Cunha often looks much more like a winger than a natural striker.

That's a sorry situation for a club like United to find itself in, and while they should still be producing better results than they are, Martinez certainly has a point when he speaks about the poor recruitment, and injuries only highlight his point.