Naturally, Koetter doesn't want to see the most prolific tight end in NFL history walk away from his offense. But he knows he has to prepare for life without Gonzalez, as the 37-year-old veteran is set to retire following Sunday's game against Carolina.
"There may never be another guy that can get himself open as consistently as that guy," Koetter said of Gonzalez. "Tony has an unbelievable knack for getting himself open, even when coverage says he shouldn't be open. I've never been around a guy like that."
Gonzalez has 172 catches the past two seasons in Koetter's offense with one game left. Koetter reflected on the best of them.
"There are a lot of them," Koetter said. "The one for the touchdown in the 49ers' game last year, the playoff game here. There are a couple of those 20-yard throws down the middle where the linebacker's facing him and has got his hand right in his face and somehow, Tony makes the catch.
"The one at the Redskins last year at the goal line, that was a great one. I mean, he's made a few."
Now going into next season, Koetter will have to orchestrate his offense without the luxury of designing plays around Gonzalez. At least he'll have plenty of tape to show his tight ends on how the position is supposed to be played.
"There's something to that," Koetter said, "but I don't know if you can take a guy who's got an 'S' on his chest underneath there and tell other guys to be like that."
With more than 15,000 career receiving yards and 210 consecutive games with a reception, Gonzalez is truly one of a kind.