Dominic Thiem defeated Milos Raonic in three sets to secure a place in the BNP Paribas Open final at Indian Wells, where Rafael Nadal withdrew from the other semi-final against Roger Federer because of a knee problem.
Nadal's knee appeared to flare up in his quarter-final win over Khachanov on Friday, where he twice received treatment from his trainer, with the Spaniard stressing after the match he would need to assess the injury ahead of the match on Saturday.
The Spaniard looked in discomfort during the match and only had a brief practice session on Saturday.
It would have been the 39th career meeting between Nadal and Federer, who advances to Sunday's final in pursuit of a record sixth title at Indian Wells.
Federer will now play the victor of the tournament's other semi-final between Austria's Dominic Thiem and Canadian Milos Raonic.
Nadal had been seeking his fourth victory at Indian Wells, where he last triumphed in 2013.
"It's not about only during the tennis careers that I am anxious", he said.
Manchester United drawn against Barcelona in Champions League quarterfinals
In fact, you have to go as far back as April 2013 to find the last time Barca's leading goalscorer netted in a last eight tie. Naby Keita is still a doubt, although Klopp did suggest he might make a decision on him based on a late fitness test.
Thiem advanced to his third Masters final, and his first on hard court after losing on clay in the Madrid Open in 2017 and 2018.
Federer, meanwhile, broke Pole Hubert Hurkacz once in each set for a 6-4 6-4 win in the first career meeting between the pair and was perhaps more bothered by his early start. "After last year's tough loss against Juan Martin [del Potro], I would love to go all the way again".
But the overwhelming sentiment was good wishes for Nadal's speedy recovery, starting from his opponent Federer who posted a sweet video montage of their clashes.
Tournament organisers confirmed the 32-year-old's withdrawal, giving tendonitis in the knee as the reason for Nadal's retirement.
"I was trying to fight, compete and believe I can do it", Hurkacz told reporters. Federer has triumphed in both of their hard court matches. Nadal didn't drop a set in reaching his fifth Australian Open final, where he lost to Djokovic.
Federer has flown through the draw thus far at the first Masters 1000 event of the year, winning all eight sets he has played.