The Spaniard's right knee flared up in the second set of his 7-6 (2), 7-6 (2) victory over Karen Khachanov in Friday's quarterfinals.
"I am used to playing with some issues, so I just tried to be focused".
Old rival Federer still lies in his path, yet Nadal did not have it all his own way against Khachanov either and was required to battle back from an early break.More news: Florida does 'just enough' to topple No. 9 LSU
After 38 career meetings, Nadal leads the series 23-15, but Federer holds a slight 11-9 advantage on hardcourts.
"It's a bit different", the Swiss told reporters. "I can not guarantee how I'm going to wake up tomorrow morning". What can I say? "He's at a higher level than he was at the Australian Open... especially in a place like Indian Wells, where he feels comfortable, he's clearly very tough to play". "I'm very excited to be in the semis here, not that I didn't expect it".
The Swiss great has won the last five in the series, but says that's of little significance now that it has been nearly a year and a half since their last meeting in the Shanghai Masters final in October 2017.More news: Developer Of 2D Beat 'Em Up Castle Crashers Teases Switch Release
For me, it would be great to compete on my 100% tomorrow.
"He's changing directions all the time (with his serve) so it's really hard to read it".
The pair have 37 men's Grand Slam title wins between them, 17 for Nadal and 20 for Federer - the latter being a record in the sport - and have contested one of the most enthralling on court rivalries ever seen, often on the biggest stages and sharing mammoth reigns as world number one.More news: Jurgen Klopp says Liverpool don't need another summer spending spree