LONDON, April 20 (Reuters) - Coventry City will seek to revive the spirit of 1987 as they try to pull of a shock and beat Manchester United ( MANU ) in the FA Cup semi-final at Wembley on Sunday.

The Midlands club won the Cup for the only time in their history that year, upsetting Tottenham Hotspur in a thrilling final, but the intervening years have been a struggle and six years ago they were playing in the fourth-tier League Two.

However, under the shrewd management of Mark Robins, the Sky Blues are moving in the right direction again and last season were one game away from returning to the Premier League having lost their place amongst the elite in 2001.

Promotion remains the long-term priority for the club, but on Sunday it is all about the FA Cup and trying to beat a Manchester United ( MANU ) side also struggling to revive past glory.

"For us, we know they are clearly favourites to win this game by a million miles and they are expected to win," former Manchester United striker Robins said.

"We know that and what we are likely to encounter, but we have to play a part in the game. We have to understand what the game will be and what the occasion is.

"There shouldn't be any fear and it will be one of the biggest games most of our players will have played in."

Coventry have only reached the FA Cup semi-finals twice in their history and their most recent visit to Wembley left a bitter taste as they lost to Luton Town in last year's Championship playoff final.

"We've had an experience of Wembley, varying levels of success, other than last year it's been very positive, and we look forward to this weekend," Robins said.

Coventry stunned top-flight Wolverhampton Wanderers in the quarter-finals but Robins says Manchester United ( MANU ) will be a formidable hurdle despite criticism of their form.

"It's a difficult challenge, there's no doubt about it. I hear people saying Manchester United ( MANU ) are this or that, but the truth of it is they have top, top players," Robins said.

Coventry will be backed by 36,000 fans at Wembley and one thing for sure is they will match the volume of United's fans.

"They're like having an extra man when they're cheering and chanting, and they get right behind us and give us that extra bit of energy," Ellis Simms, who has scored five goals during the Cup run, said. "We thrive off the fans and the more there are, the better it is."