The 28-year-old more or less retired from rugby in 2019 when he badly injured his shoulder during a pre-season game for Otago.
He suffered nerve damage and had come to terms with the fact he may never play again.
Hammer switched his focus to coaching but it was always in the back of his mind he might be able to slip on the boots again and contribute in a limited way if his beloved Eels needed him.
They needed him on Saturday. Back-up halfback Kase O’Neill is out for the season with a broken jaw, so Hammer came off the bench and played the final 20 minutes against Green Island at Peter Johnstone Park.
"I’m not sure it is the beginning of a comeback," Hammer said.
"I’m not sure what to call it. I suppose it is a comeback but only to help out Taieri and help out my team."
Before making his cameo off the bench he sough medical opinion and "it took a wee bit of convincing myself".
His shoulder still gives him "grief every day" but he is closing in on 100 games for a club which "has given so much to me".
"It is a wee bit of a driver," he said. "I thought I may as well try and rack up another four games and get the pocket changed on the blazer."
Hammer played the last of his 13 games for Otago in the Ranfurly Shield defence against Thames Valley in 2019.
A few weeks later he injured his right shoulder during a pre-season game for the Sassenachs.
The expected three-month lay-off turned into something much more permanent.
Last year he told the Otago Daily Times unless there was a "miraculous" turnaround he would not be playing rugby for the foreseeable future.
Hammer made his debut for Otago in 2017, having fought his way back from a bowel operation to remove a growth earlier in the year.
"My shoulder still affects me in daily life. But my view of rugby has changed quite significantly.
"I’m just coming in to do a different job. I’m probably not capable of playing rugby the way I used to because I can’t actually train as I would want to.
"So my game is at a level below but it is something I can’t change too much."
