However, Dolphins head coach Adam Gase does not think Gore's age is an issue.
"It's irrelevant," Gase said regarding Gore's age via the Palm Beach Post. "He's a different dude."
Gore played for the San Francisco 49ers in 2008, when Gase was a 49ers assistant coach.
"It's been 10 years since we were together," Gase said. "I mean it seems like forever. The guy looks exactly the same."
Gore's statistics over the past several years do not indicated a sharp decline.
He rushed for a career-best 1,214 in 2012, and in the seasons after that had rushing totals of 1,128 yards, 1,106 yards, 967 yards and 1,025 yards before gaining 961 yards while starting all 16 games for the Indianapolis Colts last season. His 3.7 yards per carry in 2017 did match a career low, however.
Gore currently ranks fifth in NFL career rushing with 14,026 yards. He needs just 76 yards to pass Curtis Martin for fourth place, and is 1,243 yards behind Barry Sanders, who ranks third on the list.