Top seed Rafael Nadal has pulled out of this week's Mexican Open in Acapulco after aggravating the leg injury that forced him out of the Australian Open in January.
The world number two, who was due to face fellow Spaniard Feliciano Lopez on Wednesday, said he felt a sharp pain during his final training session on Tuesday and decided not to compete on the advice of his medical team.
Nadal said: "It is impossible now today to say something realistic about if I'm going to be in Indian Wells or not my goal is to be there and I'm going to work to try and be there but of course, I can't say yes or no now. I hope the tests will be as positive as possible and then let's see."
Meanwhile Juan Martin Del Potro was untroubled in his first-round match against the German Miklail Zverev.
The Argentinian won in straight sets 6-1, 6-2 and faces the Spaniard David Ferrer in the second round.