With more and more NFL teams running a 3-4 defense, front offices have been looking to this year's draft class to find athletic linebackers who bring toughness to their front seven.
The Texans, however, run a 4-3 and have two linebacker positions already locked up with Pro Bowler middle linebacker DeMeco Ryans and outside linebacker Morlon Greenwood.
The remaining outside position will go to either Kevin Bentley or Chaun Thompson, free agents who signed with the Texans in March, or second-year pro Zac Diles.
Still, that doesn't mean the Texans will stop looking at what's available. Here is a breakdown of the top linebacker prospects in this year's draft.
1. Keith Rivers, OLB, USC (6-2, 236): In 49 games at USC, Rivers started 35 contests, finishing with 240 tackles (139 solos), 5.5 sacks for minus 42 yards and 18.5 stops for losses of 77 yards.
He earned the reputation as a tough athlete with excellent play-reading ability and the range to make plays in pursuit. Trojan coaches even utilized him at safety in various zone coverage packages because he fluidly can drop back into coverage.
Rivers performed well at the Senior Bowl workouts, where he showed the strength to shed blockers and make huge tackles. And an outstanding Pro Day performance erased any doubts that in scouts minds' after Rivers had elected not to work out at the combine.
In front of hoards of pro talent scouts, Rivers recorded a 42-inch vertical jump, which was a full eight inches better than any outside linebacker recorded in Indianapolis last February. He also impressed talent evaluators in the 40-yard dash, clocking a time of 4.51 seconds.
2. Dan Connor, MLB, Penn State (6-3, 231): Last season, Connor ranked seventh in the nation with a career-high 145 tackles (69 solos) and registered 6.5 sacks for minus 50 yards. In his four-year career, he broke the Penn State career record in tackles with 419.
Connor has experience at inside and outside linebacker, but he shines in the middle where he can showcase his quick reactions and playmaking ability. He impacts every facet of the defense. In 2007, Connor led the Nittany Lion defense to top-15 national rankings in rushing (No. 7), scoring (No. 7) and total defense (No. 11), as well as No. 2 in sacks (46) and No. 10 in tackles for losses (102).
His draft stock rose considerably after impressive performances at the Senior Bowl. He didn't work out at the combine because he was ill, but made up for his absence with a stellar performance at his Pro Day in mid March where his 40 time (4.67 seconds), three-cone drill (6.76 seconds), vertical jump (35 inches) and bench press (22 reps at 225 pounds) put him among the elite scores of inside linebackers tested this year.
3. Jerod Mayo, MLB, Tennessee (6-1, 242): Mayo moved to middle linebacker last season and started all 14 games there, recording a career-high 140 tackles (79 solos).
Most scouts were impressed with Mayo's versatility before the combine, but he helped himself in Indy by performing better than expected in drills. Mayo recorded a blazing 10-yard split of 1.50 seconds on the way to clocking a 4.54 in the 40-yard dash.
At his Pro Day in March, he improved his combine vertical jump by more than 8 inches to 40.5 and bench-pressed 22 reps after passing on that event at in Indy because of a sore pectoral muscle.
Mayo's stock continues to rise, and some scouts now see him as a first round pick.
4. Quentin Groves, OLB, Auburn (6-3, 259): Groves moved from defensive end to outside linebacker late last season but was hampered most of the year by dislocated toes. Despite the injuries, he still exhibited an explosiveness that has drawn comparisons to Cowboys Pro Bowler DeMarcus Ware.
Groves, who tied the Auburn career record for sacks with 26, is a classic speed rusher who would thrive as an outside rusher in a 3-4 scheme.
The senior helped himself with a solid workout at the combine, including a 40-yard time of 4.53 seconds.
His biggest downside has been off-field issues, including a domestic dispute and driving on a suspended license.
5. Xavier Adibi, OLB, Virginia Tech (6-2, 232): In four years at Virginia Tech, Adibi notched 291 tackles, 11 sacks, 30 tackles for loss and five fumbles. And he is more athletic and agile than his stats convey.
Adibi excels in coverage because of his speed and quickness and he is an effective rusher. The biggest question has been his size.
His combine workouts didn't do much for his stock, as he finished with a 40-yard time of 4.69 and an injury prevented him from bench-pressing. But scouts see a great deal of potential in this senior.
Honorable mention: Oklahoma's Curtis Lofton (6-0, 246) has proved he can make explosive hits, but lacks the size of an elite middle linebacker. He also hurt himself at the combine with mediocre performances in drills and a rather pedestrian 4.81 40-yard time. Maryland's Eric Henderson (6-3, 244) has the size to play outside and cover tight ends, but the outside linebacker was plagued by injuries, including a torn ACL, during his collegiate career.