Tennis fans were enjoying a real treat of a match between world no. 7 Novak Djokovic and no. 4 Daniil Medvedev, who had split the first two sets of the Astana Open semifinal on Saturday. It looked like the third set between Djokovic and Medvedev was going to be real battle. Unfortunately, there was no third set.

Medvedev was forced to withdraw from the match due to an injury. Afterwards, Djokovic was asked about his peer being forced to retire from the contest- and the 21-time Grand Slam winner revealed his shocked reaction, per Tennis TV.

Novak Djokovic said the following, “I'm still surprised that he retired the match. He looked completely fine, maybe last seven, eight points I've seen him move slightly slower, but it's a shock honestly. I was ready for a third set battle. I really hope his injury is nothing too serious. I know Daniil, he's a great guy, he's a fighter, he's a big competitor, he wouldn't retire a match if he didn't feel that he couldn't continue or to worsen his injury…”

Novak Djokovic went on to add that Daniil Medvedev told him he “pulled the adductor muscle in his leg.”

To Djokovic, it looked like there was nothing wrong with Medvedev, who was playing the level of tennis that saw him secure the world no. 1 ranking earlier in the summer.

Clearly, though, there was something going on with Medvedev physically. As Djokovic respectfully acknowledged of his tennis peer, Medvedev is a “big competitor”, so there had to be a reason why he would relinquish a match that was still up for grabs.

It's not the first health issue that has popped up for the Russian tennis star this year. Medvedev missed six weeks due to hernia surgery before returning back in May. Now, he's dealing with another physical ailment, to the shock of many.

Including Novak Djokovic.