Owen Hargreaves claims Manchester United defender Luke Shaw has now overtaken Liverpool's Andy Robertson as the best left-back in the Premier League.
Shaw is enjoying a purple patch on the left-side of the Red Devils' defence over the past six weeks, scoring in the Manchester derby away at City whilst also adding four top-flight assists since the beginning of February.
Robertson, meanwhile, was the English top-flight's best left-back last season as he helped Liverpool to a first league title in 30 years - but both the Scottish international and Jurgen Klopp's Reds are struggling this season.
And former United midfielder Hargreaves claims Shaw's upturn in form - which also led to an England recall on Thursday - means he is a vital figure for the Red Devils when star midfielder Bruno Fernandes is not in form.
Speaking about Shaw before United's Europa League tie at AC Milan, Hargreaves told BT Sport: 'He's earned the shirt, right now. He's the best left-back in the country.
'Last year it was Andy Robertson, now it's Luke Shaw. If he's fit and healthy, he's one of the best he's proved that.
'It's been Luke Shaw and Bruno Fernandes, rotating the player of the months roles. He's been magnificent. When Bruno Fernandes has had a quiet day, he (Shaw) has stepped up.
'In the last six weeks he's been fantastic. Luke on that left hand side has been fantastic in terms of creating more than anyone apart from Bruno Fernandes.'
Robertson was one of the star Premier League defenders last term, with 12 top-flight assists and two goals as Liverpool dominated the title race.
But the Scotland captain as struggled to replicate similar numbers and has not registered a goal or assist in all competitions since December 19.
Liverpool have also flopped in their title defence and currently lie in sixth-place, 25 points behind leaders Manchester City and five points behind fourth-placed Chelsea.
Shaw and United, meanwhile, have lifted themselves up to second place while Ole Gunnar Solskjaer's side are also targeting success in the FA Cup and Europa League competitions.
Fellow United midfielder Paul Scholes claims Shaw is benefitting from having recognised striker Edinson Cavani at the club, which is giving him the opportunity to show his true worth at Old Trafford.
Scholes told BT: 'You've seen him put a lot of crosses into the box and we've had a proper centre-forward in Cavani in there. His delivery has been brilliant and there's no shock really.
'He's kept himself fit now and he's had the longest run of games in a united shirt. He's showing the benefits from it.'