Mack did not attend OTAs and hasn’t made any official decision on whether he’ll continue to play or retire, according to Matt Maiocco of NBCSportsBayArea.com.
The 36-year-old Mack started all 17 games and made the Pro Bowl last season, and the 49ers would like to have him back. He has two years left on his contract and is due a $5 million base salary this season.
The 49ers don’t have a great option in house to step in if Mack retires. The backup center is Jake Brendel, who has played a grand total of six offensive snaps over the last three seasons. The 49ers have also indicated they might give rookie offensive tackle Nick Zakelj, a sixth-round draft pick out of Fordham, an opportunity to play some center.