The Spaniard successfully defended his Indian Wells title last month and then reached the Miami Open quarter-finals before injuring his right forearm during a practice session in Monaco.

Alcaraz, who missed the Monte Carlo and Barcelona tournaments before making a comeback in Madrid, said he had tweaked his style slightly on the advice of his coach "Juanqui" - Juan Carlos Ferrero.

"When I want to hit a forehand hard, I'm asking myself how the arm will react. It's there in my mind," the world number three said after beating Thiago Seyboth Wild 6-3, 6-3 in the third round on Sunday.

"Juanqui tells me to go with a relaxed hand and that's what I do.

"I still don't trust 100% the forearm. I have doubts, it's just in my head. I love competing, so from time to time I want to go hard and I think about it.

"I can't say that I play at a lower percentage, I play differently. You're used to seeing me push my forehand to 200% several times in matches. Juanqui tells me I don't need to go that far.

"I'm happy with my game and with the ball's trajectory. I'm moving well, feeling good and I have no pain. I just need time to let these thoughts go away."

The second-seeded Spaniard, who is seeking a third straight trophy in Madrid ahead of next month's French Open, next plays Jan-Lennard Struff in a rematch of last year's title clash.