Manchester United are lining up their next signing after yet another defeat to Chelsea.

It's no win in the past in all competitions for manager Michael Carrick, who watched his 10 men suffer yet another loss at Stamford Bridge at the weekend, with Lisandro Martinez dismissed for two yellow cards in quick succession.

With January fast approaching, Manchester United are looking to address the glaring issues with their squad – and Martinez may well be a beneficiary of the club's next signing.

Manchester United looking to strengthen in January

The Red Devils had a modest summer in the transfer window, strengthening with the likes of Youri Tielemans, Carlos Baleba and Andrey Santos in midfield – but neglecting other areas of the pitch.

Left-back has been a concern all season, with first-choice Luke Shaw currently out injured, and young prospect Patrick Dorgu failing to impress there (also injured right now), with Diego Dalot filling in in recent weeks.

Sport Witness have now reported on United's interest in Alejandro Balde, with the full-back struggling for game time under Hansi Flick's high-flying Barcelona.

After bursting into the first team from Barça's famed La Masia academy, Balde hasn't held down a first-team place this season, with Joao Cancelo and Xavi Espart preferred in Flick's back four.

Now, Mundo Deportivo sources claim the 23-year-old is up for sale, with the Blaugrana concerned about his concentration in defence.

United tested the waters over the summer for Balde, only for the Spanish international to opt to remain in Catalonia and fight for his spot at Camp Nou – but following the start of this season, he is now “attracted to the idea” of a move to revitalise his stagnating career.

While a new left-back could well give the struggling Martinez a new lease of life next to him, there are certainly concerns over Balde's recent form, should United rekindle their interest.

While Carrick's side have their issues in attack – and an overlapping full-back like Balde would certainly bring more out of whoever plays on the left wing – the defensive frailties at Old Trafford are just as worrying.

The 20-time English champions have conceded nine in their previous three fixtures across the Premier League and Champions League.

Balde is worth €40 million, according to Transfermarkt. United take on Roma this week, as Champions League action continues.