Manchester United manager Louis van Gaal is ready to consult a fatigue specialist as he decides whether or not to play forward Anthony Martial against West Ham United on Tuesday night.
Martial missed the most recent game, a 1-0 win over Norwich City on Saturday, after feeling muscle tightness during the warm-up and withdrawing at the last minute.
Despite securing a win at Carrow Road through Juan Mata's goal, United lacked spark in attack without Martial and the rested Marcus Rashford, so the availability of the Frenchman could be a key factor in determining the outcome at Upton Park.
Discussing Martial, Van Gaal said: "I don't take any risks as he's a very important player. We don't want a rupture because he's very important to us."
A complication for Van Gaal is that United face Bournemouth at home on Sunday, meaning there is little recovery time ahead of the next match. He also has to consider players' fitness with an eye on the FA Cup final against Crystal Palace at Wembley on May 21.
When Martial missed the game against Norwich, he was replaced by Memphis Depay, who failed to make a positive impact.
The Dutchman also filled in for Martial when the France forward was ruled out against FC Midtjylland and Arsenal in February. The return of Rashford, however, could lead to a reorganised attack with Depay missing out.