ALLEN PARK, Mich. Chris Harris wanted another shot to play when his second stint with the Chicago Bears wasn't going very well.

Chicago cut him loose last month and Detroit jumped at the chance to claim him.

The Lions have already benefited from the seemingly savvy move.

"We got lucky," Detroit coach Jim Schwartz said Tuesday. "It's hard to find experienced safeties, particularly in the middle of the season. When called upon, he can go make a play, which he did in the Carolina game."

Schwartz subbed Harris into Sunday's comeback win over the Panthers in place of starting safety Amari Spievey because Spievey missed one too many tackles.

Harris, a seven-year veteran, took advantage of the opportunity with two tackles and an interception in the fourth quarter that helped seal the victory over another one of his former teams. "They know what I can do here," Harris said Tuesday. "And they know I'll be ready whenever they call my number."

When Detroit (7-3) hosts the defending Super Bowl champion Green Bay Packers (10-0) on Thanksgiving, it might not count on Harris right away.

Spievey was on the field with the first-string defense in the early part of Tuesday's practice.

If Spievey, a second-year pro, struggles again, though, Harris provides quite a backup plan with nine games of starting experience against the Packers.

The Lions have lost two backup safeties to season-ending injuries, Erik Coleman and Vincent Fuller, making Harris the third player they've plugged in as a reserve at the position. They caught a break when Chicago cut Harris on Oct. 28 and were able to add him the next day.

Harris, a sixth-round pick in 2005, has 16 interceptions in 83 starts and seven games as a reserve.

He had five interceptions last season, tying for the team high in Chicago, and started this year's opener. He missed the next three games with a pulled hamstring, then struggled as a starter when he came back against Detroit and Tampa Bay. Later, he was benched and asked for a trade.

"We don't all of a sudden wake up one morning and just say, `Hey, we're going to go this direction,"' Bears coach Lovie Smith said last month. "It's a pattern and I feel good about the decision that we had to make."

At least some of his former teammates in Chicago were surprised by the move, and so was Packers quarterback Aaron Rodgers.

Rodgers said he respects Harris because he's a smart player who understands route concepts and recognizes formations.

"I feel like with him and (Brian) Urlacher back last year that was the big reason their defense made the improvements they did," Rodgers said. "Obviously, Julius Peppers helped, but having Chris and Brian back was a big part of their success."