“Sean Weatherspoon is going to be an important part of building this defense and building this team,” Falcons general manager Thomas Dimitroff said. “He has that side of him and that leadership that we need across the board.”

Weatherspoon was not happy last season as the defense descended to the bottom of the league. He took umbrage with the weekly updates on where the defense was ranked.

He’s been working diligently and has started to run seven months into which could be an 8-to-10 month rehab.

“He’s a guy that’s really, really focused on his rehab,” Dimitroff said. “We need him back in this organization to help us go to another level. He’s starting to move around.”

Weatherspoon, the team’s first-round pick in the 2010 draft (19th overall), was headed into a contract season before rupturing his Achilles tendon while running with the training staff in June.

Weatherspoon, 26, was coming off a tough campaign in 2013. The 6-foot, 1-inch and 241-pound linebacker, spent part of the season on injured reserve/designated to return with a foot injury before making it back, only to exit again with a knee injury.

After the surgery, Weatherspoon faces a long recovery period.

“For him to go back to being an inside linebacker, he’s going to be out closer to four or five months, but once he’s healed he has to rehab again,” said Dr. Phillip Kwong, a foot and ankle surgeon at Kerlan-Jobe Orthopaedic Clinic in Los Angeles.

The rehab from an Achilles tendon injury is arduous.

“He’s going to be very weak with his push-off,” Kwong said. “He’s not going to have the strength to have explosive movements pushing off. That’s mainly it. The weakness of the calf muscle doesn’t give you good control of your knee and your ankle. That’s going to limit his ability to push-off, run and change direction.”

The Achilles is not a career-ending injury. Former Falcons cornerback Brent Grimes came back from an Achilles and returned to Pro Bowl form for the Dolphins after he wasn’t re-signed.

“It doesn’t have to be career-ending,” Kwong said. “If they can repair it properly and rehab him properly so that he has good movement on his ankle up-and-down and side-to-side, then if he (regains) good strength, he can come back.”