The Australian Open is unlikely to have ever seen a better credentialled world No.338 but Juan Martin del Potro is just happy to be heading to Melbourne Park at all.

The big Argentine’s comeback tournament ended with a quarter-final loss at the Sydney International on Thursday to Kazakhstan qualifier Mikhail Kukushkin.

With his second serious wrist injury in five years keeping him out of much of 2014 the former US Open champion was simply glad to be back.

There’d certainly be no predictions for the grand slam opener.

“We go day by day. It’s dangerous for me if I’m looking forward for the next tournaments or the next month,” said del Potro, who didn’t have a break point against him in the 7-6 (7-5) 7-6 (7-3) loss.

“But I got lucky playing three matches in this tournament against good players. I’m here; I’m still alive. I feel tired, but okay.”

Del Potro admitted his wrist, which had also kept him out of much of the 2010 season, was beginning to hurt but thought it was to be expected after seven sets, including three tie breakers, in three days.

He’ll be a player any seed will be keen to avoid next week.

Kukushkin said he felt for del Potro who struggled for a full range of shots.

“He’s a top player, but I think everyone saw today that he cannot yet hit full power in his backhand,” he said. He did a lot of slices. For sure this affects his game. Still, he serves good. His forehand was working okay today.”

It’s now six wins in a row for the plucky world No.66 at Sydney Olympic Park after three victories in qualifying.

He will now play Argentine Leonardo Mayer in a semi-final after his 6-3 7-6 (7-4) win over 2012 finalist Julien Benneteau.