The biggest free-agent signing of the NFL offseason made the competition tighter in the NFC South.

The Tennessee Titans lost the mountain in the middle of their defense when free agent defensive tackle Albert Haynesworth left for Washington and the biggest contract ever for a defensive player. Haynesworth’s deal effectively pays him $12 million a year, and he gets $41 million guaranteed.

All of a sudden, the Titans don’t look quite as dominating as last year, when they won 13 games and held home-field advantage in the AFC. The Haynesworth-led Titans defense ranked sixth in the NFL against the run last year and second in points allowed. The Titans still have lots of defensive talent. But the door is open for Indianapolis to knock them off their perch and for Houston and Jacksonville to gain ground.

Here’s a look at the offseason in the AFC South:

Tennessee: Big Al leaves big hole in defense.

Indianapolis: Caldwell steps into Dungy's big shoes.

Houston: Did 27th-ranked defense get better?

Jacksonville: Del Rio aiming to get physical.

Tennessee Titans

Key gains: WR Nate Washington (Steelers),WR Brandon Jones (49ers), WR Kenny Britt (Rutgers), DT Sen’Derrick Marks (Auburn), TE Jared Cook (South Carolina), DT Jovan Haye (Bucs).

Key losses: DT Albert Haynesworth (Redskins),KR Chris Carr (Ravens).

Breakdown: The Titans’ good track record for drafting and developing defensive linemen will be put to the test. The 320-pound Haynesworth is gone. The defensive tackles are Tony Brown (290) and Haye (285), who was a rotational player in Tampa. The Titans are high on DT Jason Jones (275), a second-round pick who had five sacks last season. DE Javon Kearse is coming off knee surgery. The Titans were quick to stick with Kerry Collins, age 36, at QB. Vince Young rides the pine. The pass offense ranked 27th. Washington is a deep threat. Brandon Jones is an average slot receiver.

Questions: How much better can the offense, which ranked 21st in yards, get? Cortland Finnegan is a star at corner. Can Nick Harper, going on 35, hold on at the other side? Can the middle of the defense be bullied?

Indianapolis Colts

Key gains: RB Donald Brown (UConn), DT Fili Moala (USC), DT Terrance Taylor (Michigan),WR Austin Collie (BYU).

Key losses: Coach Tony Dungy (retired),WR Marvin Harrison (cut), RB Dominic Rhodes (Bills), P Hunter Smith (Redskins).

Breakdown: Jim Caldwell has been grooming as an aide to take over for Dungy for the last seven years. He has a great personnel department and a great quarterback on his side. The Colts ranked 24th in run defense. In a departure from the Dungy style, they drafted two heftier DTs in Moala (305) and Taylor (319). Overall, the defense ranked 11th in yards allowed. Key cogs were re-signed. CB Kelvin Hayden inked a rich deal. Jeff Saturday, who will be 34, returns at center, much to Peyton Manning’s delight. Ex-Bill Pete Metzelaars is the offensive line coach.

Questions: The running game ranked 31st, which is why Brown was drafted. Young Mike Pollak and Jamey Richard (UB) are penciled in to start at guards. With Harrison gone, Anthony Gonzalez steps up at WR. Can Collie emerge as the third WR?Is the LB corps good enough, with Tyjuan Hagler, Gary Brackett and Freddy Keiaho? Free safety is unsettled.

Houston Texans

Key gains: DE Antonio Smith (Cardinals), LB Brian Cushing (USC), DE Connor Barwin (Cincinnati), LB Cato June (Bucs), DT Shaun Cody (Lions).

Key losses: QB Sage Rosenfels (Vikings), RB Ahman Green (cut).

Breakdown: The Texans won five of six to close the year at 8-8 but they never have had a winning season. Most fans don’t realize the Texans offense ranked third in the NFL in yards. Smith and Cody join the starting Dline with Mario Williams and Amobi Okoye. Smith played OK in the regular season but looked great in the playoffs for the Cards. If he keeps it up, the Texans have book-end stud rushers. Cody is just a guy. The Texans put the franchise tag on CB Dunta Robinson.

Questions: Will the moves bolster a defense that was 27th in points allowed? A secondary that includes CB Jacques Reeves, SS Nick Ferguson and FS Dominique Barber doesn’t scare people. Is the WR corps good enough after Andre Johnson?

Jacksonville Jaguars

Key gains: WR Torry Holt (Rams), OT Eugene Monroe (Virginia), OT Eben Britton (Arizona), OT Tra Thomas (Eagles), RB Rashad Jennings (Liberty), DT Terrance Knighton (Temple).

Key losses: RB Fred Taylor (Pats), LB Mike Peterson (Falcons), DT Paul Spicer (Saints),WR Matt Jones (cut), WR Reggie Williams (cut), OT Khalif Barnes (Raiders).

Breakdown: The Jaguars lost their swagger in falling from 11 to five wins. The offseason focus was on rebuilding the smash-mouth run game. So three tackles were added. Jennings, a good value, can back up Maurice Jones-Drew. The Jaguars missed Marcus Stroud last year.

Questions: The search for a solution at receiver continues. Holt, who turns 33 next month, should help where so many have failed. Are Mike Walter, Dennis Northcutt and Troy Williamson good enough as his cohorts? Depth at cornerback is a worry. Can second-year DEs Derrick Harvey and Quentin Groves rush the passer?

Next: AFC West.