Long snapper Patrick Mannelly always did listen well. For 16 years and 245 games — the longest tenure of any Bears player in history — Mannelly, 39, was a bastion of stability as he watched more than 750 players come and go. He took the same calm approach after having hip surgery Jan. 23, knowing general manager Phil Emery had made him a standing offer to return if he felt healthy enough to do so. ‘‘I said I’d listen to my body,’’ Mannelly said. ‘‘And my body’s tapping me on the back and saying: ‘That’s it, bud. I think you’re done.’ ’’ His retirement Friday transcended his accomplishments on the field, even as his career spanned a generation. Selected in the sixth round out of Duke in 1998, Mannelly was the last active Bears draft pick made by the late Mark Hatley. At the time, running back Ka’Deem Carey, whom the Bears picked last month, was 5. Mannelly played for four of the 17 coaches in Bears history. ‘‘It’s difficult to talk about Patrick as a player in the past tense,’’ chairman George McCaskey said in a statement. Mannelly took a mental snapshot before his first regular-season snap, looking between his legs at punter Todd Sauerbrun in Week 1 of the 1998 season against the Jacksonville Jaguars. He did it again in January 2007, when the Bears won the NFC Championship Game at Soldier Field.