Statistically I believe he does. On average, he gives the ball away 12.2 times per game (Source: Premier League stats from SofaScore), which is higher than any other player this season except Kev. For reference, Foden is at 11.8, Alvarez is 10.8, Rodri also 10.8, Jack 7.8.
Also worth noting that Doku has only played an average of 60 minutes per game in the Prem (for comparison's sake, Phil is at an average of 82 minutes per game). So his average amount of possession turnovers is actually worse than it looks at first glance (12.2 every 60 minutes compared to, for example , Phil at 11.8 every 82 minutes).
Doesn't mean Doku won't play and can't be a great asset in this game but I don't see any merit in overlooking or denying one of the weaker aspects of his game at the moment. We'll want to keep Madrid's chances as minimal as possible, especially at their ground, and I'd probably prefer to see a more control-oriented lineup, even if it means we don't create quite as much, just to make sure we get back to our place with the tie alive and within our grasp.