Ian Maatsen is starting to find his feet in top-flight football while on loan at Borussia Dortmund.

After a tough first half of the season with parent club Chelsea, the 21-year-old left-back opted to gain vital experience in the Bundesliga.

In the 39 days since his temporary switch was made official, Maatsen has spent more minutes on the pitch than he did under Mauricio Pochettino's rule in West London.

Ahead of Dortmund's Champions League last-16 clash at PSV Eindhoven this evening, we take a closer look at a potentially career-defining decision by the young Dutchman.

A case of the Blues

At the end of the 2022-23 campaign, Maatsen looked ready to make an impact in a Chelsea shirt. 

He had just enjoyed a hugely successful loan stint at Championship winners Burnley, helping Vincent Kompany's side post 101 points from their 46 matches.

Maatsen featured in 39 of the Clarets' league fixtures, registering four goals and six assists — stats which saw him named in the second tier's PFA Team of the Year.

But despite returning to a Chelsea side who had just finished 12th in the Premier League last summer, the Dutchman could not nail down a regular spot in Pochettino's starting XI.

He was restricted to just 199 minutes of action across 12 appearances in the top flight, while making just two starts in the Carabao Cup.

Dortmund dynamo

Maatsen's fortunes have changed upon arriving at a Dortmund side in desperate need of a new left-back following Julian Ryerson's serious knee injury.

He has started all six of the Bundesliga games for which has been available, assisting a goal in victories over FC Koln and Freiburg.

The full-back is excelling in key metrics too, ranking inside the division's top 30 for final third passes completed per 90 minutes, through balls executed per 90 and big chances created per 90.

Maatsen also sits an impressive 10th for possessions won in the defensive third per 90 — and Terzic is well aware of the difference he has made to Dortmund.

The German coach, 41, said: "Ian is a very young player, but already has a lot of experience under his belt. We've been following his progress for a long time.

"He brings a lot to the table, both from a technical and physical standpoint.

"He gives us another dimension in the build-up play because he also feels very comfortable in the middle."

PSV reunion

Maatsen will be eager to continue his bright Dortmund form against PSV — the club he represented for three years at youth level before joining Chelsea's academy in 2018.

On paper, it looks as if it will be the sternest examination of his quality yet.

PSV have turned the Philips Stadium into a fortress this season and Maatsen is set to come up against one of the star men for the Eredivisie leaders in Johan Bakayoko.

The Belgian right winger, 20, has scored four goals and assisted eight more in league action — and his direct playing style could see the Dortmund ace have to forgo some of his marauding bursts forward.

But if Maatsen delivers on the big stage, it could prompt Netherlands head coach Ronald Koeman to hand him a first senior call-up ahead of this summer's European Championship.