Ryan Giggs says watching Manchester United is confusing and has urged his former club to produce a complete 90-minute performance in their Champions League return with Juventus.

United were outclassed when the two sides met at Old Trafford two weeks ago, with Paulo Dybala’s first-half winner scarcely reflecting the vast superiority of the Italian champions.

Jose Mourinho’s side did mount a late charge in that 1-0 defeat – with Paul Pogba striking a post – and it has been a constant theme in recent weeks that United have started badly in games before awakening in the second half.

United produced dramatic comebacks to beat Newcastle and Bournemouth, and also recovered from a 1-0 deficit at Chelsea to lead 2-1 before drawing.

“I’ve been really impressed with United in the last four or five games, especially second half,” United great Giggs said ahead of their Turin return.

“But I don’t know what it is. As a United fan you are scratching your head.

“Bournemouth on Saturday were brilliant in the first half, but United were brilliant in the second half. It’s just putting that 90 minutes together.

“They have proven they can give anyone a game, but if you don’t turn up for 45 minutes you will not win.

“You have to turn up for 90 minutes and United have the players.

“They were second best the other week, but I think it will be closer on Wednesday.”