The key battles that will define Leeds United's play-off showdown with Derby County

There was a suspicion after ‘Spygate’ blew up that football’s penchant for a good story would make them cross paths again and the final weeks of the season pulled the pair together like magnets.

Leeds have had Derby’s number on the pitch, scoring six goals against them from open play and limiting County to one long-range free-kick from Tom Lawrence during a brutal 4-1 defeat in August, but Marcelo Bielsa was loathe to assume that Derby would be there for the taking in the play-offs. With Saturday’s semi-final first leg looming, this is how the key protagonists match up:

Kelle Roos v Kiko Casilla

The goalkeeping situation at Derby is a rather fluid.

Frank Lampard has Scott Carson available to him, an old-school veteran who grew up in an era when keepers were keepers, but Dutchman Kelle Roos is Derby’s current No 1, despite being out of contract in the summer, and more suited to the concept of operating as an 11th outfield player.

He could not be placed in an elite bracket in the way some would Kiko Casilla, although Casilla did a poor job of showcasing his talent at Ipswich.

The Spaniard’s trademark sprints from his box can be heart attack-inducing and he has not been the sensation a signing from Real Madrid should have been but in essence he is the keeper Bielsa wants: willing to hold a very high line and compel Leeds to play from the back. Roos by all accounts has barely put a foot wrong for Lampard, recording seven clean sheets in 16 league appearance.

Bielsa will be crossing his fingers that Casilla’s rushes of blood at Ipswich are not about to be repeated.

Richard Keogh v Liam Cooper

There are no frills with Richard Keogh but the limitations and occasional errors in him do not alter the fact that he knows more about the play-offs than anyone in either camp.

This is the fourth play-off campaign of his career and Lampard will want Keogh’s knowledge to guide a fairly young squad at Pride Park.

Cooper has transformed himself into a completely different breed of centre-back this season and, at his best, helped to dictate Leeds’ tempo and direction of play with quick but patient distribution from the edge of his own box.

Keogh has a higher pass completion percentage and tends to get on the ball almost as much as Cooper but it was Cooper who made the EFL’s team of the year and Cooper who has had the better campaign. As the clubs’ respective captains, so much is on them in a psychological sense.

Mason Mount v Mateusz Klich

Mount - a Chelsea kid who went very close to a first England cap in October - was made to look like a myth in Derby’s defeats to Leeds.

He touched the ball 25 times during their 4-1 loss and was made to look his age when Lampard’s side were beaten 2-0 at Elland Road in January.

But he has talent and a willingness to get on the ball in difficult areas, bringing other players into games, and he has a tidy tally of 10 goals. When injury took him out of Lampard’s line-up in February and March, Derby felt the impact.

Klich, who completed an ever-present term on Sunday, is a more robust and physical midfielder but his influence in the second half of the season has not been what it was in the first half. This is an area where the play-off semi-final is likely to be won and lost.

Harry Wilson v Pablo Hernandez

Wilson’s goals have made more headlines than his general performances - some spectacular finishes from set-pieces and open play - but he has pace and good acceleration and Lampard likes his wingers to be very direct. Hernandez is a different footballer in many respects: far older and more travelled at 34, more inclined to drift off the flank and looks for pockets of space in the middle of the pitch, and a talisman with his overall influence, not just his goals.

He is way out in front of Wilson when it comes to assists and key passes but both wingers have the potential to make something of nothing.

Hernandez, though, is one person who should manage the pressure of an all-or-nothing semi-final, provided he can rediscover the spark which left him a few weeks ago.

Martyn Waghorn v Kemar Roofe

Derby have a big concern about the fitness of Waghorn, who aggravated an Achilles in Sunday’s win over West Bromwich Albion and was in a protective boot as Lampard’s players did a lap of appreciation at Pride Park.

Lampard likes his physicality and over time, Waghorn has become his centre-forward of choice in a front three. One more goal would take him to double figures in the Championship. Roofe has already scored twice against Derby and the frustration for him and Leeds is the knee injury which took the shine off him three months ago, leaving him a little rusty at a point where he would want to be perfectly sharp.

Only two players in the Championship produce more shots per game than Roofe and Derby found his movement very difficult to read in both previous meeting between the clubs.

Waghorn, in contrast, barely figured in those contests and, as a substitute at Elland Road, touched the ball nine times in the 20 minutes he was on the pitch.

That is the sort of suffocating dominance Bielsa craves.