Sherman told NFL Media's Michael Robinson (via NFL.com's Conor Orr) on Saturday that he could see Lynch changing his mind and returning for the 2016 season.
"I don't put anything past him," Sherman said. "He's about as predictable as a pair of dice. ... You would hope he comes back. In the back of your mind, you hope he comes back and plays another year."
Seahawks wide receiver Doug Baldwin seemed sure about Lynch's retirement when he discussed the impact of the loss of the running back on NFL Network on Thursday (via NFL.com's Chris Wesseling).
"Everything that he's done for us, not only on the field but also being our main stable leader in the locker room, we're going to miss him," he said. "It's going to be hard to go along without him."
The possibility of Lynch returning is still real. As of May 12, Lynch had not officially retired, according to the NFL on NBC:
Seattle has had a taste of life without Lynch. He appeared in only seven games last season because of injuries, totaling just 417 yards and three touchdowns on 3.8 yards per carry.
In his place, Thomas Rawls rushed for 830 yards and four scores while averaging 5.6 yards per carry. He broke his ankle near the end of the season, but Rawls looked like a capable back as a rookie in 2015.
Seattle finished third in the league in total rushing yards.
The Seahawks also drafted three running backs in the 2016 NFL draft: C.J. Prosise in the third round, Alex Collins in the fifth round and Zac Brooks in the seventh round.
Prosise provides a solid receiving threat out of the backfield, while Collins is an excellent power runner with lateral quickness.
If Lynch does decide to come back, it seems likely that the Seahawks would find room for him. However, given its offseason moves, Seattle seems to believe he is gone for good.
With Rawls and a stable of rookie running backs in the fold, Seattle's running game is in great shape moving forward. It still has a dynamic rusher at quarterback with Russell Wilson, so it can continue to utilize the read-option game the offense relies on.
All statistics are courtesy of ESPN.com.