Former Celtic striker Andy Walker has insisted that Rangers must look to his old club for lessons on how to generate transfer income.

Ryan Kent and Alfredo Morelos look set to depart Ibrox this summer for nothing after letting their contracts run down, with manager Michael Beale explaining on Friday that neither of the pair have been offered extensions thus far.

Nicholas believes that Rangers could have banked significant fees if they had sold the duo earlier on in their Ibrox careers as he urged Gers bosses to take a leaf out of Celtic’s book when it comes to the club’s overarching transfer strategy.

READ MORE: Former Villa striker Gabby Agbonlahor claims he rejected Rangers transfer interest

Appearing on the Go Radio Football show, the pundit explained: “It's been a strange one. I've got absolutely no problem with any player honouring their contract but I think Rangers have played this one badly.

“These players [Kent and Morelos] were worth - both of them - a lot of money a couple of years ago. And if the answer is they had to keep them to win the title a couple of years ago to stop Celtic doing 10 in a row, maybe that's the price Rangers have paid. But my goodness, it's a high one.

“I think you could've got something between £10-15million for Kent and something similar for Morelos a couple of years ago when they were at their peak when they were doing well in Scottish football and European football.

“And that's a lot of money and I think Rangers need to learn how to do business, they need to learn how to sell.

“You look at Celtic, if anyone leaves tomorrow, there's no real shock. You'll get someone else in because that has been the way of it.

READ MORE: Celtic defender and women's team star's relationship confirmed during derby

“Celtic spent, I think it was £8-9million on Edouard a few years ago. Now that's a huge deal but they still made money on him. And that's what you need to do with players.

“I've said it all season, get them in for a small fee, fatten them up, sell them on and 'thanks for coming to play for a short time'. I think Rangers need to learn how to do good transfer business.”