CELTIC and Rangers must act quickly if either are to secure the services of Charlton Athletic defender Alfie Doughty after Stoke City tabled a bid of £650,000, according to a report.

The two Premiership rivals have been tracking the left-sided player for some time with the Parkhead club seeing two bids for Doughty knocked back in the summer, while Steven Gerrard's league leaders are also said to be monitoring the 21-year-old.

The Daily Mail report that Stoke boss Michael O'Neill is a big fan of the youngster and the English Championship club have made their move with an opening bid of £650,000.

Glasgow Times:

READ MORE: Charlie Adam insists Celtic will need 'brand new team' as ex-Rangers star slams Jeremie Frimpong

However, with Doughy's contract up at the end of the season, the wide player is free to discuss terms with other clubs with a view to joining in the summer on a free transfer - a deal which is understood to be preferable to the two Glasgow clubs.

But they will need to act fast to ensure they don't miss out after Stoke's opening bid for the in-demand full-back.

The Addicks defender has already informed the club that he will not sign an extension with the League One outfit and ultimately, the final decision rests with him.

If Doughty were to sign for Celtic or Rangers, a small development fee would have to be paid - similar to the deal to bring Joe Aribo to Ibrox from Charlton in 2019.

Glasgow Times:

READ MORE: Celtic striker Odsonne Edouard steps up plans to leave Parkhead at first opportunity

The Ibrox club shelled out £300,000 on that occasion - a fraction of his estimated worth in the market - and Charlton boss Lee Bowyer is determined to ensure he doesn't lose another prize asset on the cheap.

He told the Mail: "If Alfie does leave then it will have to be the right thing for the football club.

"No one player is bigger than the football club and Alfie is no different.

Glasgow Times:

READ MORE: St Mirren boss Jim Goodwin ‘absolutely delighted’ with capture of Eamonn Brophy

"Alfie's agent has told us he won't sign a new deal and I'm disappointed with that.

"But that's his decision, that's his choice we understand that."