Unfortunately it was Diallo who gave the ball away in the first place though. He was sloppy as all hell last night. Some of his passing was woeful, and he still seems to need too much time on the ball. I also feel he isn't strong enough. He gets shoved off the ball or pulls out of challenges that Romeu would absolutely relish.
That said, he grew into the game as it went on, so I guess we can put it down to 'rust'. And he has shown promising signs in games before; his dribbling and ball-carrying are both really good, and he can pick a pass. He's just very hot-and-cold. One great pass, followed by one howler, etc.