Scott Brown has credited manager Brendan Rodgers for making Celtic's players fitter this season, as they attempt to end the domestic campaign unbeaten.
The Bhoys saw off Partick Thistle 5-0 on Thursday evening to edge closer to an invincible first term at the helm for Rodgers, whose side are currently 30 points clear at the top of the Scottish Premiership.
Celtic have already secured the Scottish League Cup and are one game away from adding the Scottish Cup to their trophy cabinet, with Brown grateful to his latest Parkhead manager for potentially extending his career by a couple of years.
"I spoke to the gaffer when he first came and he asked how long he thought I could keep playing," he is quoted as saying by the Daily Mail. "I thought, 'great question', and I was thinking maybe two years at the highest level. Now I'm thinking I can go three, four years easily.
"As long as I'm playing, enjoying it and as fit as I am, I don't see why not. In the 91st minute at Partick I ended up on the left wing trying to close the goalie down. That has never been seen by me in the last five or six years. It shows that I still have that energy and desire to keep going for 90/95 minutes.
"We're a lot fitter than we have ever been. We are scoring more goals, creating more chances, and we look like a right good team. It's more intense training, short, sharp when it needs to be, but everyone's had to open up their lungs. It's been enjoyable this season but it's been really hard. It's been dedication from everyone as well."
Celtic face Hearts on Sunday afternoon in their final league game of the season.