Arsenal manager Mikel Arteta would not reveal if striker Gabriel Jesus had travelled for the first leg of his side's last-16 Europa League tie against Sporting Lisbon on Thursday.
Brazil forward Jesus, who has not played since December because of a knee injury, trained in London on Wednesday before the squad flew to Portugal.
When asked in Lisbon if the 25-year-old was also there, Arteta remained coy.
"We have brought a few players and you will see on Thursday who is available."
Jesus has returned to full team training since suffering the knee injury at the 2022 World Cup and having surgery on the problem.
The former Manchester City forward has scored five goals and registered six assists in the Premier League for the Gunners.
Arteta says Jesus, who joined league leaders Arsenal last summer, will not be rushed back.
"We will try to make a fair assessment between what he needs and when he is comfortable as well as giving the team a boost that it's going to need in the next few weeks for sure," said the Spaniard.
"Everything is going well, he needs time as well to get himself that confidence and that physical state necessary to compete with a free mind and once he's free to do that, we will throw him in."