CINCINNATI -- Tyler Eifert enjoyed the free trip to Hawaii and the full slate of events that preceded last season's Pro Bowl. But the Cincinnati Bengals tight end vowed Friday never again to appear in the all-star game after a freak ankle injury sidelined him for much of the offseason.

"It's just not worth it," Eifert said.

The injury could keep him out the first game or two this season, although Eifert remains optimistic he will be fully rehabbed before then.

"Everything's going well," Eifert said, hours before the Bengals opened training camp. "I'm not putting a timeline on it or anything like that. There's a long progression that you’ve got to go through here to return to play. You've got to be watched by a lot of different eyes, go through a lot of different steps.

"I'm just going to keep working hard and control what I can control and be back as soon as I can."

Eifert was hurt in the middle of the fourth quarter of the Pro Bowl when Tampa Bay Buccaneers quarterback Jameis Winston overthrew him in the back of the end zone. After leaping for the high pass, Eifert landed awkwardly on his left foot and immediately requested to come out of the game.

"It's kind of a fluke thing," Eifert said Friday. "My foot just kind of hit the turf. I didn't really turn it or anything like that. I just got my cleats on the ground and my foot kind of twisted."

Postgame tests didn’t reveal major damage, and similar tests in Cincinnati a couple days later came back negative, too. With the right amount of rest, Eifert was expected to be OK by the time the Bengals kicked off organized team activities in May.

But he wasn't. A ligament that he tore on the play didn't heal properly. Buried just behind the ball-shaped bone on the inside of a person's foot, the ligament is in a spot that's often difficult to tear, Eifert was told. Doctors also told him the injury, for unknown reasons, was common in tight ends.

Once simple rest and rehab didn’t get Eifert to 100 percent by May, he underwent surgery. The recovery time from it has his return expected to fall near the start of the season.

"It's a fine line between you want to push it and you want it to get better, but you've got to figure out why it's not getting better. You go hard and you take a couple of days off and it's still sore," Eifert said of his early offseason regimen. "It's just about getting to the bottom of what's going on."

Eifert has been in a walking boot the past six weeks. It will come off next week, and at that time, he will begin testing his ankle with mobility and other range-of-motion exercises.

Eifert has been able to keep up his conditioning in recent weeks with weightlifting for his upper body, riding a stationary bike and pushing himself on elliptical machines. Although he's disappointed to miss training camp, he doesn't think it will take long before getting back in midseason form. Last year, he paced NFL tight ends with 13 touchdown receptions.

"We'll get it back," Eifert said. "I don't think we just lose it over an offseason. So I think we'll be all right."