Holger Rune hasn't been playing superb tennis at the Hopman Cup and it's actually because he's been sick which is also the reason why he won't play at the Croatia Open in Umag.
Rune was set to appear at the 2023 Croatia Open in Umag but the Danish player won't be playing at the ATP 250 event after pulling out due to an illness. The Danish player was in Nice recently, playing for Denmark in the Hopman Cup, but he's been far from his best.
You didn't need to be familiar with the way Rune plays to quickly understand that something was very wrong with the way he played in Nice. We got some clarification on that from the Danish media in the meantime.
According to EkstraBladet, Rune was feeling ill for the whole duration of the Hopman Cup spending 4 days in bed with fever. He opted to play because it's a national competition but it would have been wiser not to have played.
While playing, Rune also developed pain in his wrist again as well getting some pain in the upper back. Much of that could be because of the illness as opposed to some injury but as a precaution, Rune will miss the Umag event and focus on getting better before embarking on a trip over the pond to the US Open.
Some big events are coming up with two Masters events as well as the US Open and carrying some sort of illness or pain wouldn't be a great thing for the Dane. The Danish media reports also indicated that Rune didn't want to accept being sick at first however there was very little he could do to prevent it.
Because of that, Rune is out of the Croatia Open, with his return date unknown as of now. He last played at the Hopman Cup where he lost both of his matches.