HALLE, Germany — Tommy Haas is largely unsure what the future holds for him, but he does have one set plan this week.

“On Wednesday,” Haas said, “I’m going to have two beers.”

The drinks will commemorate the first anniversary of Haas’s most recent right shoulder operation, his fourth, which kept him off the tour for nearly a year. Through a lengthier absence than most players ever face in a career, Haas has experienced two year-plus layoffs from the tour, for his first shoulder operations and a hip operation.

“Obviously, at my age, I don’t have that much time to waste,” he said.

Haas is 37, an age by which most professional tennis players have been retired for years. But after another round of rehabilitation, massages and injections, he has worked his way back to the tour once again. He made his return on grass courts in his native Germany, winning one round in Stuttgart last week and losing in the first round of the Gerry Weber Open on Tuesday afternoon.

“It’s great to be back; at the same time, it’s a lot of work,” he said. “It’s nerve-racking. Lots of emotions go through your mind when trying to make the comeback, because at the same time you kind of know how you want to play, what kind of tennis you want to play, and practice is so different than matches.