The Celtic striker made his first appearance since 7 October, scoring with a free-kick just eight minutes after coming on as a substitute to wrap up the Premiership leaders’ 3-0 win at Hamilton Accies.
Griffiths has struggled to attain the physical condition demanded of him by manager Brendan Rodgers but believes he is now ready to start making a consistent contribution again.
“It was nice to be back on the pitch,” said the 28-year-old. “It has been a frustrating five or six weeks for me, trying to build my fitness up. So to come back and score like that was great. Hopefully I’m firing on all cylinders again.
“Speaking with the management and sports science staff, there was no secret that I was a bit heavier looking. Over the course of the six weeks, I’ve managed to drop a lot of weight. I’m feeling a lot, lot sharper and hopefully I can take my chance now whenever I get on the pitch.
“It was dark times. There was a lot of frustration in it. You just have to get on with it, do your rehab properly. It didn’t help that I was ill for ten days which took a bit out of my recovery time.
“I also had a slight calf problem, although not as bad as it has been