US Open champion Stan Wawrinka has played down an ankle complaint suffered in his Brisbane International semi-final loss on Saturday.

Japan’s world No.5 Kei Nishikori won through to the Brisbane men’s final by ousting second seed Wawrinka 7-6 (7-3) 6-3 in just over 90 minutes at Pat Rafter Arena.

Third seed Nishikori will play Bulgaria’s world No.17 Grigor Dimitrov in Sunday’s decider.

World No.4 Wawrinka appeared out of sorts from the outset and took off his shoe court-side after taking a 5-4 lead in the first set.

The three-time grand slam winner received assistance from a physio a game later.

But Wawrinka did not appear concerned ahead of the Australian Open.

“No, I don’t think so. Just something with my ankle but nothing special,” Wawrinka said.

“Today I had some little pain but that didn’t affect my game today.

“I think it was, in general, a really good level (of play) today.”

Overall it has been a sluggish start to the year for Swiss star Wawrinka despite receiving a first round bye in Brisbane.

He is yet to hit top gear, labouring over three sets to beat unseeded Brit Kyle Edmund in the quarter-finals before having no answer for old sparring partner Nishikori.

Former US Open runner-up Nishikori levelled their overall head-to-head record at 4-4 but has won three of their last four meetings.

“We know each other really well. We played many times against each other and practice, also, a lot,” Wawrinka said of his Japanese foe.

“I think today he was really aggressive, was really strong from the baseline, didn’t give me much.

“(But) I think my level, in general, was good.

“I had three good and tough matches, playing better each match.

“Today I didn’t take my opportunity but I think the level, in general, was really high for first week of the year.

“I’m really disappointed to lose in a semi-final but I have to take some positives from the week and go with that.”