Why Unai Emery must decide if he’ll stick or twist as Aston Villa face Marcus Rashford and Marco Asensio conundrum, writes TOM COLLOMOSSE

In five games, Marcus Rashford and Marco Asensio have given Aston Villa a tantalising glimpse of their talent, but Unai Emery’s loan stars cannot solve his greatest problem.

The pair have made their presence felt in less than a month at Villa Park, with Rashford registering three assists and Asensio scoring twice to help Emery’s men fight back from a goal down to beat Chelsea.

Yet as second-half substitutes, they were helpless to turn the tide this week as Villa were thrashed 4-1 at Crystal Palace, one of their worst displays of the season.

Villa certainly look more dangerous with Rashford and Asensio on the pitch, but there is a trade-off when the opposition have the ball.

That is partly why both were excluded from the starting XI as Emery decided to match Palace’s wing back system – not that it did Villa any good.

Against Liverpool, Chelsea and Crystal Palace, Villa gave up 51 shots. Now, as he navigates a gruelling schedule of 10 games in 40 days across three competitions with their season on a knife edge, Emery’s challenge is to find the most effective balance among his attackers.

Both players have shown what they can do but are unable to fix Aston Villa’s biggest problem

Emery has to find the right balance between his attackers, considering defensive abilities

Before that, though, Villa must plug the leaks that threaten to undermine their season. They have kept only three clean sheets in 28 Premier League games and, though they are still in contention for a top-five finish, it is difficult to see how they can achieve it without becoming more solid at the back.

On the face of it, Cardiff at home on Friday in the FA Cup looks a handy draw and, though Villa lost to Club Bruges in the first phase of the Champions League, they will feel capable of beating the Belgian champions over two legs in the last 16.

Emery’s initial success at Villa was built on seven players — Emi Martinez in goal, a back four of Matty Cash, Ezri Konsa, Tyrone Mings and Lucas Digne, plus Boubacar Kamara and Douglas Luiz in central midfield.

Luiz has left, Mings missed 14 months with a serious knee injury and Cash and Konsa have spent time out of action due to muscle injuries.

Indeed, Emery has been left perplexed by the number of muscle issues his team have suffered. As well as Cash and Konsa, Amadou Onana, Ross Barkley, John McGinn and Kamara have all been sidelined this season, while Martinez had to be replaced at half-time at Palace with a tight hamstring.

Though Martinez has not been quite as sharp as he was last season, the gap between the Argentine and his back-up Robin Olsen is huge. As well as being a fine goalkeeper, Martinez’s ultra-confident demeanour on and off the pitch inspires his team-mates.

A quieter personality, Olsen simply does not have the same presence and when Martinez is missing, Villa seem to shrink.

Mings needs time to recover completely from such a dreadful injury and, while skipper McGinn is a vital cog in the machine, leadership does not come as naturally to him as it does Mings or Martinez.

Villa have kept only three clean sheets in the league this season and that could ruin their year

The likes of Matty Cash (left) and Ezri Konsa (right) have spent time out injured this season

This is where Rashford and Asensio can help. Asensio has won 21 trophies for Real Madrid, Paris Saint-Germain and Spain, while Rashford has spent his life at one of the world’s foremost clubs. Only Martinez and Digne can match their experience of being in the spotlight.

The pair should start against Cardiff, but in other games Emery may decide that risk outweighs the rewards. Mail Sport examines the choices facing the Villa manager as he handles his highest profile signings.

Villa with both Rashford and Asensio

With Ollie Watkins the first choice as No 9, Villa’s most threatening trio behind him is Morgan Rogers on the right, Asensio in the middle and Rashford on the left.

This was the combination that started the second half against Chelsea last Saturday and it worked a treat, with Rashford operating virtually as an orthodox winger, Asensio at No 10 and Rogers able to drift in off the flank on the other side.

In the last five games, Villa average 15.5 shots per game, compared with 12.9 before Asensio and Rashford joined.

While that number will be inflated by the 25 shots Villa took in the 1-1 draw with 10-man Ipswich, it is significant that Rashford, Asensio and fellow winter arrival Donyell Malen average more shots per 90 minutes than all other current Villa players.

The flipside is that with the loan stars involved, Villa conceded their highest xG (expected goals) of the campaign against Palace, their second highest against Liverpool and their fourth highest against Chelsea.

Repeating the Rashford/Asensio formula against the strongest teams leaves holes elsewhere in the line-up.

Ollie Watkins is Villa’s best No 9 – and the club can field a threatening trio behind him

The most dangerous three to play while in possession would be Asensio, Rashford and Morgan Rodgers on the right

… how about with Asensio only?

Asensio is arguably the best technician in the squad, but cannot give the team what McGinn or even Rogers offers without the ball.

As Emery sees his fellow Spaniard as a No 10, his presence also shunts Rogers from the centre to the right, where he is not quite as effective. Yet in an Asensio-only set-up, Emery can protect the on-loan Paris Saint-Germain player.

When Kamara returns from a hamstring injury, he would slot straight back into central midfield, with Jacob Ramsey or McGinn on the left. Both those players offer more defensively than Rashford, though they cannot strike the same fear into full backs’ hearts that a fit, focused Rashford can.

Chelsea defender Malo Gusto is probably still recovering from the chasing Rashford gave him at Villa Park last Saturday.

Playing all three, though, leaves holes – one option is playing Asensio and not Rashford

… or playing Rashford without Asensio?

It is pretty clear where Emery views Rashford at his best – wide on the left, almost as an orthodox winger.

He beat Gusto on the inside and outside and it was a surprise that Chelsea boss Enzo Maresca did not switch Reece James to right back to counter his sometime England colleague.

Without Asensio in the team, Rogers can move to his favoured central role, where he has been highly effective this season. Unless Villa are chasing the game, Rashford’s inclusion means the man on the opposite flank plays inside.

McGinn can do that, as can Malen and Leon Bailey, although having Bailey and Rashford together would put considerable strain on Villa’s defence.

While Watkins is the starting No 9, Rashford and Malen appear to be developing a promising understanding.

Malen should have scored against Chelsea after running on to Rashford’s pass and is the understudy to Watkins in that role. With Rashford thought to be still only about 70 per cent fit, Emery is optimistic about what he can still offer.

Rashford is at his best on the left – and the Man United loanee is still thought to be only 70 per cent fit

Not playing Asensio would give Emery the freedom to play Morgan Rogers centrally – where he has been at his best this season

Rashford is striking up a strong relationship with Donyell Malan, though he is not in Villa’s best XI right now

What if emery selects neither of them?

We have seen this film for much of the season – a side who, Rogers and Jhon Duran aside, look stodgy and predictable going forward.

Bailey was struggling to recapture the levels he showed during the first half of last season, Watkins did not look himself and injury had interrupted the progress of Ramsey, Barkley and Onana. Emery missed the goals of Luiz – sold to Juventus – and McGinn.

Yet Rashford and Asensio can also be effective, even when they are not initially on the pitch. Two of Rashford’s Villa appearances came as a half-time substitute, which gives Emery greater options and keeps the starters on their toes.

Before bringing in Malen, Asensio and Rashford, Emery had a preferred starting XI which he would alter only to lock down a result or when things were going wrong. Now he is looking at fixtures and deciding which players would be stronger starters and which more effective finishers.

In the Champions League it may be another matter. Villa lost at Club Bruges in the first phase and when they travel there again next week in the last 16, Rashford and Asensio may start on the bench against the hard-running Belgians.

With both lying in wait, Bruges will be far nervier than they were in the autumn. Unless Villa can work out how to keep the back door shut, though, the flair of their famous duo will count for precious little.