Ashley Young will miss Manchester United's Champions League match at CSKA Moscow.
Young was absent from the 3-0 win over Everton on Saturday because of a calf injury and the winger did not take part in United's final training session ahead of Wednesday's match.
Paddy McNair, who suffered liver damage playing for Northern Ireland last week, missed the session at the AON Training Complex in Carrington on Tuesday morning.
Youngsters Sean Goss, who went on the summer tour of the United States, and defender Regan Poole were also involved.
James Wilson trained, but is set to be left out of the squad for the game, along with Young, McNair and long-term injury victim Luke Shaw.
"It's the same amount of injuries so Luke Shaw, Paddy McNair and Ashley Young are not going with us," United manager Van Gaal told MUTV.
"Willo was a little bit ill - Wilson as he is named but, for us, it is Willo - so he shall not travel with us.
"I'll take 20 players with me. It's a four-hour flight so, if a player gets ill, I have the other player in my environment."
Antonio Valencia and Sergio Romero missed the win at Goodison Park because they had long-haul flights after the international break, but both look likely to travel to Russia.
"Of course that was the reason [Romero and Valencia were absent at Everton]," the Dutchman added.
"They have to cope with the jet-lag so I didn't think it was wise to take them with us against Everton."
United fly to the Russian capital on Tuesday afternoon before taking on CSKA the following day.