Substituted early in the second half of Manchester United‘s 2-1 win over Arsenal at Old Trafford, a foot injury means striker Romelu Lukaku is a doubt for the upcoming FA Cup final.

In a slow-paced encounter indicative of a late-season fixture between two clubs with cup priorities on their minds, United snatched a last-gasp victory over the Gunners, in what will be Arsène Wenger's final trip to the Theatre of Dreams as Arsenal boss, thanks to Marouane Fellaini's stoppage-time header.

In truth, it was a game of little consequence. Or at least it should have been. The loss of Lukaku, should the worst fears be confirmed, ending his season, could be a costly blow for José Mourinho's men as they prepare to take on Chelsea in the FA Cup final on May 19.

A £75million summer signing from Everton, the Belgian centre-forward has impressed in his maiden campaign with the 20-time champions, notching 27 goals in 50 appearances and showing demonstrable improvements in his hitherto maligned link play.

Therefore his absence will be felt. Lukaku has been United's most dependable scorer this term and much of the way they attack revolves around using the former Chelsea star as a focal point.

United don't have an obvious like-for-like option in reserve, so filling the void left by Lukaku's injury will require a tactical rethink of Mourinho, but they do, however, have three very viable attacking alternatives.

Marcus Rashford

Rashford was the man to replace Lukaku against Arsenal, coming off the bench in the 49th minute and looking to threaten the Gunners in behind with his pace, directness and dribbling ability.

However, the England forward made little impact, failing to shoot for goal and touching the ball just 12 times.

Considered a natural striker by most, Rashford has found the majority of his game time wide on the left in recent seasons, with his path to central minutes blocked by Zlatan Ibrahimović last season and Lukaku this.

As such, the 20-year-old appears understandably rusty when redeployed in the middle, his sharpness blunted by inaction, leading to a Premier League return of just six goals in 2017/18.

But Rashford remains the kind of striker defences cannot relax in the presence of, such is his speed, unpredictability and calmness in front of goal.

Anthony Martial

Martial has been one of United's best performing attackers this term, and can consider himself very unfortunate to have lost his starting berth to Alexis Sánchez, who arrived from Arsenal in January.

Indeed, the Frenchman's lack of recent game time is said to have caused him to consider his Old Trafford future, giving life to rumours of a potential summer move for the 22-year-old.

Like Rashford, although he prefers a central remit, Martial has been deployed mostly as a winger since Mourinho took charge of the Red Devils in 2016. However, despite this, the former Monaco youngster has remained productive when played, returning nine goals and five assists in the Premier League this term.

What's more, although his minutes have been restricted of late, Martial remains United's most creative player when it comes to expected goals assisted (5.9), and is second only to Lukaku (20.1) for total expected goals contribution (xG + xA) with 13.02.

If nothing else, this shows Martial deserves the opportunity to stake a claim for a starting role in Lukaku's absence, while his pace, combination play and deadly finishing make the France international a mobile and clinical option to lead the line.

Alexis Sánchez

Another option at Mourinho's disposal is to field Sánchez through the middle at the point of the United attack.

The Chilean thrived in such a role for Arsenal last season, breaking the 30-goal barrier for the first and only time in his career, while also reaching double figures for assists.

The 29-year-old former Barcelona man boasts intelligent movement centrally, making him a difficult prospect for opposition centre-backs, who become unsure whether to follow him when he naturally drops into deeper areas, while his pace is a threat in behind.

Mourinho has not yet opted to field Sánchez in this kind of false 9 role as yet, but the United No. 7 was so effective there at the Emirates that the Portuguese coach must consider doing so if Lukaku is ruled out for the FA Cup final.

Starting from the left side of attack, Sánchez's performances since making his shock move to the red side of Manchester have come in for criticism, but his displays of late have improved as he grows accustomed to his new surroundings, netting twice – including a key goal in the FA Cup semi-final win over Tottenham Hotspur – and registering three assists in his last five games.

All three options will require a different approach from United, as none can match Lukaku for presence, power and the ability to sniff out chances within the penalty area, but all have the Belgian beat when it comes to fluidity of movement and positional interchanging.

There is no easy answer for Mourinho when deciding who should get the nod to replace his top scorer, but Rashford, Martial and Sánchez could all come in and shine in their own way.

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