Announced on his official website, the Japanese will fly back to Florida, his permanent residence, for further evaluation and is aiming for a swift return to action.
The 27-year-old reached the final in Barcelona last year – falling to the Rafael Nadal in the final – but has battled various injuries since the start of the year.
In an official statement, he said: “I am very sorry to pull out of the Barcelona tournament. It’s obviously one of my favorite tournaments and have great memories here the last years.
“Unfortunately my right wrist is not recovered enough to play here this week.
“I will fly back to Florida with my team and work on getting back on the tour as quick as possible.”
The 27-year-old is no stranger to injury problems and has battled various ailments throughout 2017.
He struggled to last the five sets against eventual champion Roger Federer at the Australian Open in January and suffered a shock round one reverse to the Brazilian Thomaz Bellucci at the Rio Open just a month later.
He breezed through three rounds in Indian Wells but was struck by his own body in a three-set defeat to Jack Sock.
He had reached the final of the Miami Open in 2016 and was widely tipped to repeat the feat after the withdrawals of Murray and Novak Djokovic.
But Fabio Fognini proved the beneficiary of the Japanese’s injury history as he notched a notable win.