He said: "We are in a good way but we have to keep our focus on these games [against Manchester City and Chelsea] and the knockout stages of the Champions League. We have to win those games now," the German centre-back said.
"We are always looking to win something and we can achieve something with this group. We have a lively group so our thoughts are now on the next match, that is the most important thing for us, not what's going to happen in May.
"We have a few targets in our team that are possible this year. We won't talk about it, we'll just see what happens in the next few important weeks on the pitch."