Is that a reaction to the way coaches view the defense's performance so far in training camp or the preseason? Or, like general manager Martin Mayhew always says, is it just a case where there's never a finish line when it comes to tweaking the roster?
"The only message it's sending is we're going to keep on trying to add good players," head coach Jim Schwartz said. "It wasn't a reaction to anyone's play or anything else. It was more opportunity to get those guys.
"Guys that have played a lot of football in the NFL. All of them have a proven track record in the NFL."
But there is a message in these signings, even if it was unintentionally sent: perform, or this regime won't hesitate to find someone who will.
The defense has allowed 635 yards in two preseason games and didn't tackle or cover particularly well in a victory over the New York Jets last week and in a loss to the Browns Thursday night.
"They are trying to find something that works," Mathis said of bringing in veterans like himself, Bannan and McIntosh into the fold this late into camp. "They are trying to find some veteran guys who know how to play football."
Mathis, 32, spent his first 10 seasons in Jacksonville and was an All-Pro in 2006. He has 512 tackles and 30 interceptions in 129 career starts. Saturday, he was playing both safety and nickel corner.
Bannan, 34, has played for four teams during his 11-year career, starting 45 games over the past three seasons for the Denver Broncos and St. Louis Rams.
"I felt like I was wanted here," Bannan said of the reason he signed with Detroit.
He was already getting into the mix on the Lions second-team unit during Saturday's practice.
McIntosh, 30, is only two years removed from a 110-tackle season with the Redskins in 2010.
The outside linebacker played his first six seasons with the Redskins before joining the Rams in 2012. Last year, he appeared in all 16 games with nine starts.
Over his career, he's amassed 515 tackles, nine sacks, eight forced fumbles and four interceptions and has started a total of 78 games.
"They want to get something done," McIntosh said of why he was brought in. "You've got some guys (in myself, Bannan and Mathis) that have had a lot of playing time in their careers and (the Lions) want that over here and we're going to bring it.
"If they ever need somebody to fall back on, we're the type of guys that you can count on."