Kris Boyd reckons Alfredo Morelos has the fight of his life to usurp Antonio Colak from the Rangers team.

The Sky pundit feels the Colombian could shed a pound or two to get back into top condition for the season ahead.

But while Morelos has been getting back to fitness after a five-month layoff, new signing Colak has been smashing in the goals and has four in his last four games.

Boyd knows what it's like to be a Rangers striker being criticised over their weight, having been the subject of jibes throughout his career.

And he insists only hard graft is the answer for the club's talisman.

He said: "Morelos may be the club’s record goalscorer in European competition. But that counts for absolutely nothing right now.

"Not when he’s nowhere near fit enough for Giovanni van Bronckhorst’s liking.

"The fact Morelos didn’t get on the pitch against PSV spoke volumes for me.

"At 2-2 on Tuesday night, Rangers could have been doing with a lift in the closing minutes.

"Whether it was anxiety or not, the crowd had fallen flat after the Dutch side’s late equaliser and Morelos could have given everyone a boost.

"But Van Bronckhorst didn’t turn to him and, for me, that was him sending the Colombian a message. Everyone can see he’s a few pounds overweight.

"OK, he’s been out injured for a while but he’s been back training for weeks now.

"It’s as clear as day and Morelos has to do something about it — and quickly.

"I’ve been there. My weight and size was something I was constantly criticised for throughout my career.

"But ask any manager I worked under and they’ll all tell you I trained hard every single day.

"Morelos is very similar but until now he’s always relied on game time to trim down.

"But he can’t use that if he’s not getting back in the team.

"He has to get his head down in training — and away from the club — and work like never before to get back to the level he was at when Gio first arrived.

"His match sharpness will only come from games.

"But he can definitely get himself into better shape by grafting behind the scenes. There are no excuses otherwise.

"It’s time he showed what he’s made of and accepted the challenge Colak has thrown down to him.

"Otherwise he could find himself on the bench for a long, long time."