He didn't really. He came on as a late sub on his debut and scored the 5th in a 5-2 win, and got an assist in his second game, also as a substitute. Was then given a run of 4 starts during March, 3 of which they lost and in which he was substituted, two of them coming at half time. He then barely featured until he played the full 90 in the last game of the season, a dead rubber having already qualified for the Europa League, which they also lost. His 10 appearances, of which 6 were starts, averaged barely 40 minutes per game, and there were as many games he was an unused sub or didn't even make the squad.
Now I'm all for giving the lad a fresh start and, now he's here, I really hope he can recapture his form from 2/3 years ago, but please let's not try and make out that he's coming here on the back of a recent run of good form. He isn't. That's reflected in his transfer price. I don't think that Leverkuson tried very hard to keep hold of him either.