The Celtic manager has grown increasingly concerned over Griffiths’ conditioning which has seen him suffer a series of minor injuries in recent weeks, with a calf strain currently keeping him on the sidelines.
The Scotland striker has scored 13 goals in 27 appearances for Celtic under Rodgers this season, with 11 of those outings coming as a substitute.
Griffiths has effectively lost his status as Celtic’s No 1 striker to Moussa Dembele and Rodgers has now provided a stark assessment of the challenge faced by the 26-year-old if he hopes to remain a key player at the club.
Rodgers insists Griffiths’ natural goalscoring abilities – he netted 40 times for Celtic last season to be named Scotland’s Player of the Year – are not enough on their own to assure him of a place in his plans.
“Talent is not enough,” said Rodgers. “[He needs to work on] every aspect of being a professional. Leigh is a really good boy and I want to help him. If he can really focus in on [what he does] outside of the football field, he can be a consistent player for a number of years at the top level. If not, it might prove to be very difficult for him.
“That’s from the lifestyle of a footballer. You have to live it right. Unfortunately for him, he’s in this cycle of breaking down. It’s not just about the games. You have to train well, work well.
“He’s a very spirited young man which I love. He’s got personality. But hopefully he’ll have seen progression in lots of players here through this way of working. It’s total devotion to being a footballer. If he can do that, he can sustain being a top-class young striker, not just in Scotland but at Champions League level. If not, it can be difficult.
“It is not something that I have just said to him now. This is from the beginning of the season. It is why the likes of Dedryck Boyata can come in to the team recently, having hardly played a game all season, and play to the level that he has. Because every single day of his life he is training, he is working, he is preparing mentally for the opportunity.
“It is why Callum McGregor, at ten minutes’ notice after Stuart Armstrong was injured in the warm-up, can come into a game like Sunday’s against Hearts and perform at 90 minutes at a high level with big intensity when he hasn’t featured so much recently. Because he lives his life right, because he is preparing well, because he is tactically ready. Whether he is starting or not, he is prepared to play.
“If you are not, then you come in and get injured after 15 minutes, 20 minutes. You can’t not train hard, not train well and then go into a game and expect to pick up the tempo, especially with the way we press and the way we run. If you are not prepared for that then you go over the edge.
“Leigh knows. It was the same last year. He would have played but did he train? My point is you can score 40 goals in a season and that is okay from an individual perspective but I am worried about the team and the ethos of the team and how we work every day. It is something that he knows.”
Rodgers continued: “It is not by coincidence that he is injured consistently. If you are not training well then you go into a game and then because of the intensity it catches you out and you feel a bit tight.
“He is such a great lad and he has such a big heart and I want to help him. I want to help him to be a Celtic player not just for one or two seasons – he only really got into the team recently and then got in and got the goals – but to sustain it and be at the top level, and I mean the highest possible level that we can get to, then you have to be a top-level professional.
“You can’t make excuses. You have to find a way every single day to stabilise your life in order to maintain the performance. He has to help himself. There is no coincidence that lots of the other players here, in terms of fitness and tactical ideas, are improving and if Leigh can do that then he’ll be a consistent goalscorer.
“I don’t need 40 goals from him. I said when I came in, I wanted multiple goalscorers so even if he only got 20 goals we’d get the rest from somewhere else. It has to be about the ethos of the team.”