Hideki Matsuyama, the Masters champion, withdrew on Thursday from The Players Championship due to a back injury that had been bothering him since last weekend.

Bob Turner, who is a Masters champion and travels with him, said that Matsuyama strained his neck and shoulder at the Arnold Palmer Invitational. He then played it through on the weekend.

Turner claims that Matsuyama only chipped, putted and putted during practice rounds at TPC Sawgrass. He never took a full swing. Matsuyama also received treatment but didn’t feel fit enough to play.

Matsuyama didn’t plan to play next week. Matsuyama’s next event was the Dell Match Play in Austin Texas.

Matsuyama’s Augusta National title defense is less than a month away. Matsuyama was the first Japanese man who won a major at the Masters.

He is one of only two players to have won multiple games this season. He won the Zozo Championship last fall in Japan and the Sony Open in Hawaii in Jan.

Patrick Rodgers replaced Matsuyama in the field.