The 30-year-old has been with the Belgian club since 2015 and has made 346 appearances, netting 102 games.
He has started all six matches in the Belgian Pro League this season, with a goal and an assist to his name.
However, the Belgium international is reportedly desperate to join West Ham and play in the Premier League.
The Hammers are also very keen to sign him before the transfer window closes, but the Bruges-based club are unwilling to part with him.
The London outfit have already seen two bids rejected, but they are poised to make a third offer, according to the Daily Mail.
Vanaken plays as an attacking midfielder and is known for his aerial ability, dribbling, passing and through balls.
The Hammers have enjoyed a successful transfer window, signing several players including Gianluca Scamacca, Thilo Kehrer, Emerson Palmieri and Maxwel Cornet.
But the Premier League club are still looking to make new additions and are attempting to sign Vanaken, despite seeing their two bids rejected.
Despite enjoying a good transfer window, West Ham have made a disappointing start to the 2022-23 season. They have lost all their league matches and are currently at the bottom of the standings.
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