It was Djokovic’s first match since February and only his fourth in 2022.
The 34-year-old Serbian star had been forced to miss the Australian Open and many of the ATP Tour’s biggest tournaments this year due to his Covid-19 vaccination status.
Djokovic, a two-time champion at Monte Carlo, lost to the 22- year-old Spaniard in three sets, 6-3, 6-7 (5), 6-1.
In February, Djokovic lost his world No. 1 spot to Daniil Medvedev, but the 20-time grand slam champion returned to the top of the rankings three weeks later after Medvedev’s second-round loss to Gael Monfils at Indian Wells.
“You have to deal with everything that probably has been dormant inside and is maybe waiting to come out,” Djokovic said as he reflected on the Australian Open debacle.
“I’m trying to deal with it on a daily basis or weekly basis, whatever. If something surfaces, I acknowledge it, but I move on.
“It’s not something that is bothering me on a daily basis so to say, I don’t feel like it has left huge scars on me that I’m unable to train or participate in tournaments or live my life, far from that.
“But it has definitely been a very challenging few months and something I’ve never experienced before. So I’ll try to use that as a fuel for what’s coming up.”