The Atlanta Falcons replaced Michael Turner with another proven, productive running back.

Steven Jackson, the top running back in free agency, agreed to a three-year, $12 million deal with the Falcons on Thursday.

Also getting new deals were backup quarterback Matt Cassel in Minnesota, pass rusher Cliff Avril in Seattle and cornerback Keenan Lewis in New Orleans. The New York Giants signed defensive backs Ryan Mundy and Aaron Ross.

Day 3 of the NFL’s free agency frenzy was highlighted by the 29-year-old Jackson moving on from St. Louis after his eighth straight 1,000-yard season.

“I think this is a very big signing for us,” Falcons general manager Thomas Dimitroff told The Associated Press. “It continues to bolster our offensive firepower. It gives us not only strength, power in running ability but also the versatility to catch out of the backfield, which is a very important part of this offense.”

Jackson would have earned $7 million with the Rams in 2013 before he opted out of his contract to become a free agent. His 10,135 yards rushing for his career are the most of any active player.

The Falcons released Turner, defensive end John Abraham and cornerback Dunta Robinson on March 1. Turner had 800 yards rushing last season, his low total in his five seasons in Atlanta.

Jackson averaged 4.1 yards per carry with the Rams and gives Falcons quarterback Matt Ryan another receiver. Jackson had at least 38 catches in each of his last eight seasons in St. Louis.

“We’re hoping he has his best years ahead of him, there’s no question about that,” Dimitroff said. “We think he still has much fuel in the tank and I know that he believes that.”

The Broncos have gone on a spending spree for the second straight spring and on Thursday, Wes Welker, among the top prizes in this year’s free agent class, was welcomed to town.

Also introduced at the Broncos headquarters Thursday was right guard Louis Vasquez, who signed a four-year, $23.5 million contract, the largest of Denver’s seven signings so far, a number that’s surprised some seeing as how they went 13-3 last season.

“We accomplished a lot, and we’re trying to accomplish more,” Broncos coach John Fox said.