Frederick missed the 2018 season after being diagnosed with Guillain-Barre Syndrome, an autoimmune disease that weakens muscles and attacks the body's nervous system.
The four-time Pro Bowler was kept out of organized team activities and June minicamp after undergoing offseason shoulder surgery. However, the 28-year-old said in May that he was almost fully recovered from his disorder.
Joe Looney took over at center after Dallas put Frederick on the injured reserve.
The Cowboys posted a 10-6 record in 2018, with their season ending after a loss to the Los Angeles Rams in the divisional round.