Alexander Zverev says his elbow injury is still causing him problems ahead of the BMW Open in Munich next week.
Zverev played the Monte-Carlo Masters 1000 last week but lost unexpectedly in the round of 16 to David Goffin.
Afterwards the German admitted that he had a small fracture in his elbow and hadn't been sure whether he should compete at Monte-Carlo at all.
The world number six is due to play in his home country next week and has said he has had some 'special' treatment and has to remain careful while training.
"It's a small fracture. I'm still recovering at the moment, so I'm not at 100 percent. But I'm trying to get better from day to day," said Zverev.
"Before the tournament in Monte Carlo I didn't play tennis for nearly three weeks but I decided to play there.
"In this circumstances it was decent against Goffin. To beat a good player like him you need more practice. The elbow gets better week by week now."
"I had a special treatment last Friday. Since then it's on a good way. It still hinders me during serve motion and overhead balls in general.
"It has to heal completely and this will take more time. I have to remain careful with serve practice during next weeks.
"Serve was also the cause of the injury a bit. After my serve problems since 2019 I practiced serve for hours and hours on a daily basis. So I need a more calm approach now."
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