"Good to see he's getting stronger, growing up," Nishikori said.
No. 4 Simona Halep rallies to avoid upset in Ohio
"I mean, that's for sure I played too much hours on the court this week, last week. I played too much," Nishikori said after his 6-1, 6-1, 6-3 loss.
Fatigued Nishikori comes up empty against Nadal in Paris