Victor Wanyama will miss Southampton's UEFA Europa League playoff clash against Midtjylland due to a stomach infection.
Ronald Koeman's side travels to Denmark having drawn the first leg 1-1 at St Mary's Stadium last week after Jay Rodriguez's penalty cancelled out Tim Sparv's opener.
However, Southampton will have to contend without midfielder Wanyama, who has been laid low by illness.
"I hope that he will be available for the weekend [at home to Norwich City in the Premier League], but we have to wait," Koeman said.
The Dutchman also revealed that Sadio Mane, a reported transfer target for Manchester United, is a slight doubt for Thursday's second leg due to a hip problem, but vowed to attack their host with Southampton needing at least one goal to progress to the group stages.
"One thing we know is that we have to score. We have to go for it - and we will go for it," he said. "If we play on our level then I'm confident of reaching the Europa League.
"Of course you always like to play attractive football but the main thing is to win – and how is not important."