Mitchell, who signed a five-year, $25 million contract with the Steelers in March, had been sidelined for the first 10 days of training camp after reporting to St. Vincent College on July 25th with a groin injury.
Mitchell's return will allow the sixth-year veteran to work with strong safety Troy Polamalu during practice. The two have not gotten many repetitions together since Polamalu skipped the voluntary organized team activities (OTAs).
Mitchell is slated to take over at free safety for Ryan Clark , who started at the position for the previous eight seasons. The 6-foot, 210-pounder enjoyed a breakout season in 2013 with the Carolina Panthers as he intercepted four passes and notched 3.5 sacks.
Mitchell spent his first four NFL seasons with the Oakland Raiders after they took the Ohio University product in the second round of the 2009 NFL draft.