Thomas, 29, enters the final year of his contract, which pays a base salary of $8.5 million, but the safety still wants a new deal.
Thomas elected to stay away from team activities throughout the offseason and incurred financial penalties for missing Seattle's mandatory three-day minicamp, training camp and preseason action. The Seahawks wiped away those fines upon Thomas' return.
"I worked my whole life for this," Thomas said ahead of his return to the team. "I've never let me teammates, city or fans down as long as I've lived and don't plan on starting this weekend."
The injury is not considered serious, Pelissero added. Johnson should be a candidate to be designated to return after Week 8.
Johnson was slated to replace departed Boomer Richard Sherman as one of Seattle's starting corners across from Shaquill Griffin. Instead, Neiko Thorpe and Tre Flowers are now expected to take Johnson's place. The team also promoted cornerback Akeem King from the practice squad in a corresponding move, Pelissero added.