Jose Mourinho had major defensive concerns ahead of the Manchester derby, but those worries will have been allayed by some good news from Luke Shaw.

The Manchester United manager’s first-choice left-back was withdrawn from England’s opening FIFA World Cup qualifying fixture last weekend, a 1-0 victory over Slovakia in Trnava.

But the 21-year-old, expected to figure as a major part of Mourinho’s team this season, gave his manager a timely boost by revealing he was ready to play against Manchester City on Saturday.

Shaw posted: “Back at it. Derby weekend,” next to a picture of himself in training. The former Southampton defender had suffered a terrible leg break in a UEFA Champions League tie against PSV Eindhoven in September 2015.

His return to fitness means Mourinho will probably field an unchanged back-four from the side that won 2-0 at Old Trafford against Southampton on August 19, with Antonio Valencia at right-back and Daley Blind and Eric Bailly the central defenders.