Arsenal manager Arsene Wenger fears that he may lose highly-rated Spanish teenager Fran Merida.
The 19-year-old was believed to have agreed a new contract with the Gunners two months ago but Wenger admits that nothing has actually been signed.
He said: "We have not progressed there. I'm concerned, yes."
Merida has been linked with a return to his homeland, but was recently quoted as saying:"At the moment I am in talks with the boss. I told him I needed a bit of time.
"The first thing in my mind is definitely to stay here, but I have to look at a few things and we will see how things progress.
"My agent and I are only talking to Arsenal at the moment, though, and nobody else – I want to see how my situation looks here and then I will decide what to do."
Merida came on as a late substitute during Saturday's 2-2 draw with Everton at the Emirates Stadium, his 14th appearance for the club.
He missed part of the season due to his Under-20 World Cup commitments with Spain.