NFL Free Agency: Pittsburgh Steelers Sign Safety Mike Mitchell; Ryan Clark Good As Gone

Dec 22, 2013; Charlotte, NC, USA; Carolina Panthers safety Mike Mitchell (21) celebrates breaking up a pass by the New Orleans Saints during the second quarter of the game at Bank of America Stadium. Mandatory Credit: Sam Sharpe-USA TODAY Sports

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The Pittsburgh Steelers made an unexpected impact on the first day of NFL free agency, as free-agent safety Mike Mitchell announced Tuesday evening via his Twitter account that he has signed with the black and gold:

ESPN reporter Adam Schefter confirmed as much through an anonymous source, which also revealed that Mitchell was given a five-year, $25 million contract to man the free safety spot.

Mitchell, 26, was drafted in 2009 by the Raiders and played four seasons in Oakland before signing with Carolina as a free agent last offseason. The former Ohio University Bobcat made a career-best 50 tackles for the Panthers as part of a dominant defense that keyed an NFC South title.

He didn’t earn a starting spot until last fall, but Pro Football Focus ranked Mitchell as the 10th-best available safety on this year’s free-agent market. PFF rates Mitchell as especially efficient as a blitzer, competent in pass coverage and subpar against the rush.

In Pittsburgh, Mitchell will likely replace free agent Ryan Clark, a 34-year-old who has played the past eight seasons with the Steelers. Clark seemed to recognize the writing on the wall with a tweet of his own Tuesday night:

Mitchell adds to a Steelers secondary that will include cornerbacks Ike Taylor and Cortez Allen, along with safeties Troy Polamalu, Will Allen and Shamarko Thomas.

Keep it here on City of Champions for more coverage of NFL free agency from a Pittsburgh perspective.

Related: Emmanuel Sanders reportedly drawing interest from multiple teams