Defensive ends often go by handles such as a "five technique" or a "three technique" or other names that fit the NFL's different schemes.
The Steelers look at their roster today and see something else at defensive end: A disappearing technique, because that's what has happened at the position for them after losing two of their top four ends the past two days with a third still on the market.
They hope to reverse that trend today when they meet with defensive end Alex Carrington, an unrestricted free agent from the Buffalo Bills. They also will entertain nose tackle Cam Thomas of the San Diego Chargers.
And linebacker LaMarr Woodley, released this week, signed a two-year contract with the Oakland Raiders.
The most intriguing of the two visits today is Carrington, 26. He is considered to be a pure 3-4 defensive end who was a bit out of place in Buffalo's 4-3 defense before the Bills switched to the 3-4 to start last season. Carrington, a third-round draft pick in 2010, started the first three games of 2013 and was hitting his stride when he tore his thigh muscle and went on injured reserve.
That's the bad news. The good news for the Steelers is Carrington's price should not be high because of his injury and limited experience, and for a team with little salary cap room, that is important.
Carrington predicted he should be full-tilt by training camp.
"I'm not going to rush it," he told Mark Gaugahn of the Buffalo News in mid-December "I have plenty of time to recover. That was the biggest thing about it, that it happened early in the season."
Like the safety the Steelers signed Tuesday, Mike Mitchell, Carrington has the look of a younger player on the rise. He is 6 feet 5, 304 pounds and played at Arkansas State. He started six games for the Bills in 2011, but was a backup in 2012 when they committed to the 4-3 defense. He won the starting left end job in 2013, but then went on the shelf with his injury.
The Bills made him a contract offer, but with Buffalo apparently switching back to a 4-3 defense next season, Carrington felt he would be better off elsewhere in a 3-4 scheme.
He would get that with the Steelers, who are now bereft of defensive ends.
Ziggy Hood, the Steelers' first-round draft pick in 2009, became the second free agent defensive end to leave them in two days when he signed Thursday with the Jacksonville Jaguars, reportedly for $16 million over four years.
Al Woods signed with the Tennessee Titans, and Brett Keisel remains an unrestricted free agent. Those were three of their top four defensive ends last season. Only Cameron Heyward remains on the roster of those with any appreciable NFL playing time.
Hood never quite lived up to his billing as a first-round pick from Missouri, but he was a workhorse. Playing behind Aaron Smith early in his career, he did not nail down a starting job at left defensive end until 2012, after Smith's retirement. He then lost that job last season to Heyward, a first-round draft pick in 2011.
Hood, 27, played in all 80 games since he joined the Steelers, starting 46. He had 11.5 sacks, including three last season. He had no forced fumbles in his career.
While Heyward took Hood's spot at left end last season, he has mostly played on the right side, backing up Keisel. With Carrington more suited to the left, the combination of those two could work well.
Keisel, a longtime stalwart in the Steelers' 3-4 defense, is still seen as an outside possibility to rejoin the team. However, if they sign Carrington, those chances could well disappear. Keisel has said he wants to play in 2014, but his agent, Eric Metz, said he would retire before taking a job that pays minimum wage.
Keisel, 35, has played all 12 of his NFL seasons with the Steelers since they drafted him in the seventh round from BYU in 2002. He has been their starting right defensive end the past eight seasons. He missed four games last year with a foot injury.
With Hood and tight end David Johnson (San Diego) leaving, the entire 2009 draft class has vanished from the roster, following that of 2008, which was gone by last year. Guard Ramon Foster, who signed after he went undrafted, is the only one left from their rookie class of 2009.
Ed Bouchette: email@example.com and Twitter @EdBouchette.