Celtic hero John Hartson has fired a warning at Nat Phillips, making clear the Liverpool loanee is not a first-choice pick at the moment.

The Englishman has had limited game time since joining at the end of the summer transfer window.

And Hartson feels that Liam Scales, who has featured regularly under Brendan Rodgers recently, is more than deserving of his place in the team.

Speaking on Go Radio, he said: "He (Scales) stays in the team, as far as I am concerned. He has been that good and that impressive at left-side centre-back. 

“He’s comfortable on the ball. He can pass it out from the back and take it out from the back by marauding forward.

"When he plays it wide, he fizzes it wide. A proper passer of the ball. Defends well. Defends his box. Goes and heads it.

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"And he is really comfortable in possession. Doesn’t panic or look like he is under pressure. He has been so impressive.

"This was a player who was back to Aberdeen at the start of the season.

“For me, I think it’s Carter-Vickers and Scales. You have Lagerbielke and Nat Phillips, who we have brought in from Liverpool.

"You have Nawrocki and Welsh. Other than Brendan making a decison where he wants to bring him out and play one or two of the others.

"But who is the best fit right now if you are going in against a really tough opposition, then I would go for Carter-Vickers and Scales.”