The 35-year-old Haas reached the Wimbledon semi-finals four years ago but missed the grass-court tournament in 2010 because of a hip injury, one of a long series of health problems that has plagued him throughout his career.
And the German admitted that the constant talk about his previous fitness struggles is beginning to become an annoyance, insisting that people should only be focusing on his current form.
“I’m so tired of talking about my injuries, to be honest,” said Haas, seeded 13th. “I’m healthy right now. I’m playing good tennis.
“Yes, I’m 35, but there’s nothing I can do about it. I’m later in my career. These are all things that don’t matter once you get out there. I don’t get 15 Love or 30 Love every game because I’m 35. You have to win games, sets, and matches.
“I don’t get a handout just because I’ve had five surgeries in my career. It’s not like that. You have to earn everything, you know. You can’t buy ATP points to buy your ranking. It’s not possible.
“But still, yes, it’s been a struggle at times, but it’s part of life. Overall I’m healthy, I’m competing, and I’m playing the sport I love to play. Everything is good.”
But although Haas acknowledged his own good form, he stressed that he will not be underestimating his next opponent, Eastbourne champion and world number 32 Feliciano Lopez, on Saturday.
“He is a tough opponent,” said Haas. “He obviously is feeling pretty good, no question about it, winning in Eastbourne. He’s been having quite an interesting year in my eyes.”
He added: “He’s got a great grass court game, no question about it, and I’m going to have to play extremely well to have a chance to win that match.”