Speaking to TMZ Sports, Harrison addressed the possibility of arguably the greatest quarterback of all time retiring. When asked if it would surprise him if Brady didn't play this year, Harrison replied, "No."
"That's up to Tom and what decisions he and his family make as far as what he wants to do, and if he does want to continue to play, what he’s willing to sacrifice and the family is willing to sacrifice," Harrison added.
Brady has yet to report to the Patriots' offseason program, and ESPN's Adam Schefter reported Wednesday that he hasn't committed to playing in 2018.
Harrison announced his retirement Monday after a 15-year NFL career that featured five Pro Bowls, two Super Bowl titles and a Defensive Player of the Year award.
The 39-year-old spent nearly his entire career with the Pittsburgh Steelers, but he appeared in one regular-season game and three playoff contests for the Pats last season.
While Brady is 40, he is coming off a season that saw him win his third NFL MVP award. He also led the Patriots to the Super Bowl, where they fell just short against the Philadelphia Eagles.