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

Now, all three of the starting linebackers for the Falcons in the NFC championship game against San Francisco after the 2012 season, are out of the lineup. Akeem Dent lost his job during last season and Stephen Nicholas was released over the offseason.

The Falcons, who played most of last season with Paul Worrilow, Joplo Bartu, Weatherspoon and Dent in the top spots, have been revamping the unit. They drafted four linebackers in the draft.

Worrilow and Bartu, were undrafted rookies last season. Worrilow led the team in tackles with 137 and Bartu was third on the team with 96.

“The two guys who ended up playing a bunch of games and snaps for us last year, have improved and matured, Paul Worrilow and Joplo Bartu,” Smith said. “If you would have told me this time last year that those two guys, one was going to be our leading tackler and the other was going to play over 70 percent of the snaps, I would have looked at you and said ‘I don’t think so.’ They are much more mature. We went through some growing pains with them last year and that is going to pay some dividends going forward.”

The Falcons drafted Prince Shemba in the fourth round (139th overall), Marquis Spruill in the fifth-round (168th overall), Yawin Smallwood and Tyler Starr in the seventh-round, 253rd and 255th overall.

“I really like the rookie class that we brought in,” Smith said. “I think that there are three guys that if they don’t help us on defense right away, they are going to be able to help us on special teams.”