The Netherlands striker missed Monday’s FA Cup fifth round win over Preston with an unspecified injury but is likely to retain his place at the weekend after Radamel Falcao again struggled to make an impact.
"Yes, he shall be fit,” confirmed Van Gaal when asked about the availability of Van Persie ahead of the trip to the Liberty Stadium.
Falcao, meanwhile, has scored just four goals in 19 appearances since joining on loan from Monaco and cut a disconsolate figure when he was withdrawn on the hour mark against League One opposition with his side still trailing.
Van Persie himself has struggled for top form during a campaign which has regularly been interrupted by injury but is the only United player to have reached double figures in terms of goals so far this season.
Goals from Ander Herrera, Marouane Fellaini and Wayne Rooney eventually saw United overcome Preston at Deepdale and set-up a quarter-final clash against Arsenal at Old Trafford next month.