Chelsea defender Ian Maatsen is closing in on a loan move to Borussia Dortmund, as the Blues weigh up signing a replacement left-back.

Maatsen is set to join Dortmund until the end of the season in a deal which does not include an option for the Bundesliga club to buy him.

The 21-year-old has started just once in the Premier League under Mauricio Pochettino and has pushed for a move.

Chelsea hope that six months of more regular football in Germany will increase his value ahead of a permanent sale in the summer, with Maatsen having extended his contract and inserted a release clause.

The Blues accepted a £31.5million offer from Burnley on deadline day in the summer but interested clubs, including Dortmund, were unwilling to match those terms this month.

Chelsea are likely to look to cash in on Maatsen as they bid to stay in line with Financial Fair Play constraints while continuing to spend big on new signings.

Chelsea remain in the market for January incomings, with a striker, central defender and left-back all being considered.

Signing a striker remains their priority but Napoli’s Victor Osimhen and Brentford’s Ivan Toney, two key targets, are difficult and expensive to secure.

Feyenoord's Santiago Gimenez, Stuttgart's Serhou Guirassy and RB Leipzig's Benjamin Sesko have been touted as alternative options.

Chelsea are not rushing into any business unless they are certain it will help their cause this season.

Armando Broja is set for a run in the team as Nicolas Jackson begins his Africa Cup of Nations campaign with Senegal next week.

But Pochettino is increasingly open to signing a left-back. Levi Colwill, who is typically a centre-back, has predominantly be used at left-back.

Ben Chilwell is closing in on his return after nearly four months out with a hamstring problem. Marc Cucurella had surgery on his ankle in early December and remains on crutches.