Rafael Nadal will miss the upcoming Indian Wells and Miami tournaments because of a lingering right hip injury.
Nadal, who pulled out of the Mexican Open in Acapulco earlier this week, continues to be hindered by a hip injury that has plagued him for several months.
He lost in the Australian Open second round in January, then the first round at the Rotterdam indoor tournament, before retiring from his second-round match last week in Marseille, France.
The 31-year-old Nadal is a three-time former champion in Indian Wells (2007, 2009 and 2013) and has reached five Miami finals (2005, 2008, 2011, 2014 and 2017).
"We are disappointed that Rafa will not be able to compete for the third title at this year's BNP Paribas Open", Haas said.
"I've enjoyed being back on tour playing matches and this gives me even more motivation to go back on the practice court".
"Unfortunately, the injury I suffered in Acapulco before starting the tournament is in the same area as the one suffered in Melbourne", Nadal wrote in a short statement released via Facebook. "We wish him all the best for a speedy recovery".
Wawrinka is one of the strongest players on clay and reached the final of the French Open past year after winning the title in 2015.
"They are both fantastic events, but coming back from a big surgery after having played a few tournaments, I have discussed with my team that it is best for me to build on the progress and go back to practice", Wawrinka said in a statement.