NFL Media Insider Ian Rapoport reports Celek's deal can be worth up to $14 million, per a source informed of the contract. He will get $4.5 million guaranteed.
"Since Garrett entered the league as an undrafted rookie free agent in 2012, he has displayed the skill, work ethic and desire to compete at a high level in the National Football League," said 49ers general manager Trent Baalke said in a statement. "His commitment and determination to succeed are reflected in the way he conducts himself as a professional on and off the field. As an organization, we would like to congratulate Garrett and look forward to his continued development as a member of this organization."
Celek was set to become a free agent.
The 27-year-old tight end signed with the Niners as an undrafted free agent in 2012. He played sparingly his first three seasons before making eight starts in 2015.
Niners new coach Chip Kelly is familiar with the Celek family, having coach Garrett's older brother Brent with the Eagles.
Much like Brent, Garrett is a block-first tight end, which will help keep him on the field in Kelly's offense in 2016. Last year Garrett Celek blocked on 242 of his 407 offensive snaps. He earned a career high 186 yards on 19 receptions, including three touchdowns.