Andy Murray believes his serve has not progressed enough following his shock loss to Borna Coric in the third round of the Madrid Open on Thursday.
The world number one lost in straight sets to rising star Coric, who managed to break Murray's serve four times in the 90-minute encounter.
Added to that, Murray racked up no less than 28 unforced errors, adding to his frustration.
Murray believes the source of the issue to be the elbow injury he suffered earlier in the year, that prevented him from serving at 100%. While it is now healed, he is still struggling to find his range.
The ride continues for @borna_coric.
— Tennis TV (@TennisTV) May 11, 2017
"I think it was normal in Barcelona and Monte-Carlo that I wasn't going to serve as well as I would normally because I was still getting better," the three time grand slam winner told atpworldtour.com.
"But I was able to practise everything else. I was able to do everything physically. That's no reason for how I played today and the past few weeks. However, when you do miss a period of time, the most important thing is to play. I didn't for a month. That set me back a little bit.
"It's not always the worst thing losing a match, but it's sometimes the manner of how you lose the match that can be concerning or disappointing.
"I was disappointed to lose my match against Thiem in Barcelona, but felt like I competed really well and did some good stuff in the match. Today, I didn't really do any of that. That's concerning. So I need to think about exactly why that is, what I can do about it.
"Most things weren't working particularly well. When I started to go behind, I didn't find any way to improve my game or to make it more difficult for him. I just let the same things keep happening, making mistakes very early in a lot of the rallies. I wasn't building any points.
"That was disappointing because you're not always going to play your best tennis, but you can still find ways to make it difficult for your opponent. I didn't do that at all today."