Kei Nishikori made his competitive comeback Tuesday after a five-month injury layoff, only to have a disappointing loss to a qualifier in the first round of an ATP Challenger Tour event.

Nishikori, who was sidelined in August with a season-ending right wrist injury, went down to American Dennis Novikov 6-3, 3-6, 6-4 in their match at the Newport Beach tournament, a $150,000 second-tier event.

It was the second time the two players faced each other, Nishikori having beaten the 238th-ranked Novikov in straight sets in their last meeting at the Rogers Cup in Toronto in 2016.

After the 1-hour, 47-minute match, Nishikori, who was given a wildcard at the event, said he needs more time to rebuild lost confidence.

“I had expected it to be tough and it was,” Nishikori said.

“I’m not confident yet so I can’t hit aggressive shots. It’s going to take some time. I made mistakes where I shouldn’t have, and there are a lot of gaps I need to fill. There were both good and bad,” he said.

The Japanese reached the heights of world No. 4 less than a year ago but has slipped down the rankings since to find himself 24th at the start of his 2018 campaign.

Nishikori opted out of the ongoing Australian Open, the first of the year’s four Grand Slams.

Despite some concerns, Nishikori said he was so focused that he felt no pain during the match, a “good sign,” according to the four-time winner on the ATP tour. The plan is to gradually increase his training load and to raise the level of his play, he said.

The 28-year-old also said it was the first time he had played three straight sets since he sustained the injury during the Cincinnati Masters, and that, in itself, was positive.

“Just because I didn’t play well today, I’m not going to get negative. I’ll keep working hard,” he said.

KEYWORDS Kei Nishikori