TEMPE, Ariz. -- Between free agency, suspension and injury, the Arizona Cardinals lost their third, fourth and fifth-most successful defensive players at attacking the quarterback.
Karlos Dansby, Daryl Washington and Darnell Dockett combined for 14 sacks in 2013.
As a team last season, the Cardinals registered 47 sacks, tied with the Kansas City Chiefs for sixth-best in the NFL.
The good news here is that more than 40 percent of that production returns by way of John Abraham (11.5) and Calais Campbell (9.0).
Abraham though is 36, entering his 15th season, and he missed the first three weeks of training camp due to a personal matter. Campbell, meanwhile, may find it difficult to match his career-high sack total, especially given the absence of Dockett.
The Cardinals made finding another individual who could rush the passer a priority.
Enter Thomas Keiser, a three-year veteran linebacker whom the Cardinals claimed off waivers from the San Diego Chargers.
"That's the situation I want. I wanted to go pass rush for somebody," he said following his first practice with his new team Tuesday. "To be brought in here for that reason, I couldn't ask for more. It's up to me to learn the playbook and get prepared and go out there and do what's expected of me and good things should happen."
In 12 games -- including three starts last season -- Keiser, who checks in at 6-foot-4 and 260 pounds, set career-highs with 4.5 sacks and 20 tackles.
GM Steve Keim told Doug and Wolf Tuesday on Arizona Sports 98.7 FM that Keiser was "targeted all along" should the 25-year-old become available.
"(Thomas) has some natural pass rush ability," Keim said. "One thing that I felt like we were missing was a guy who can bring natural edge pressure. Thomas has done that. He's a guy that in the past three years has had nine sacks. In limited playing time last year, he had 4.5 sacks and he's got some wiggle and some bend off the edge."
Added head coach Bruce Arians, "He's played well against us for two years now. He's a very active guy."
Keiser originally entered the league with the Carolina Panthers as an undrafted rookie free agent from Stanford in 2011 and played in 12 games over his first two seasons.
How quickly he picks up the playbook and looks in practice over the next couple of days will dictate how much he sees the field in Week 1, which just happens to be against his former team on Monday Night Football.
"I'd be happy no matter who we're playing," Keiser said, "but playing the Chargers, it's a good opportunity and I'm definitely looking forward to it."