Crystal Palace look to have struck gold with the summer signing of Cheick Doucoure, as the midfielder's value has already doubled since his move to Selhurst Park.

The Malian joined Palace from RC Lens in the summer transfer window in a deal worth £21m and he has quickly established himself as an integral part of Patrick Vieira's side.

So far this season, the 22-year-old has made 12 appearances in the top flight for the Eagles, averaging an impressive 6.74 rating from WhoScored for his performances.

This ranks him as the sixth-best performer in Vieira's squad, which emphasises just how important he is becoming to the south London side, and at 22, he is only going to get better.

Doucoure's defensive abilities are already shining through with the Eagles, as he ranks second for tackles per game, third for blocks per game and top for interceptions per game in Palace's squad.

Vieira testified this earlier in the season after a defeat against Chelsea, saying:

“He is a complete holding midfielder. He can be part of our buildup and, defensively, he is winning a lot of one-against-ones. He’s growing into that role and responsibility and feeling more and more comfortable with each match. Even so, there is a lot more to come from him.”

His impressive start to life in the Premier League certainly hasn't gone unnoticed, as his market value according to Transfermarkt has rocketed since his Selhurst Park switch.

Just six months ago, during Doucoure's time in Ligue 1 with RC Lens, his market value stood at just €15m (£13.1m), but now he is rated at an impressive €30m (£26.3m), a 100% increase.

This also ranks him as the joint-fourth most valuable played in Palace's squad, behind just Marc Guehi, Wilfried Zaha and Joachim Andersen.

Therefore, it seems clear that Steve Parish struck gold when bringing the young midfielder to England during the summer, as they seem almost certain to make a big profit on him should he ever leave Selhurst Park.