Mason Greenwood, Edinson Cavani and Anthony Elanga started the 2-2 draw at Aston Villa last time out, but there could be more options available for a first game at the Brentford Community Stadium.
We will announce the starting XI at 19:00 GMT, an hour ahead of kick-off, on MUTV, ManUtd.com and the Official App. Don’t forget to enter our United Predictions competition to be in with a chance of winning a signed shirt.
When speaking on Tuesday, Ralf was hopeful Marcus Rashford and Cristiano Ronaldo would return to the squad after injury, and Anthony Martial was also in contention to travel, providing he completed the last training session in Manchester.
Jadon Sancho came on for Elanga at Villa Park but there is a doubt over Jesse Lingard, who has an ankle knock.
Pass on your opinion in our poll and read what two of our reporters feel about the possible permutations for the front-three slots…