West Ham United coach David Moyes admits he does have concerns that Joao Mario will struggle with the pace of the Premier League after he joined the club from Inter Milan.
The 25-year-old completed his loan move on Thursday after passing a medical at the Hammers training ground.
He will remain at the club until the end of the season but Moyes admits the Portugal international may be rusty at first.
Mario, a Euro 2016 winner, has fallen down the pecking order at the San Siro under boss Luciano Spalletti and Moyes admits the pace of the English game may surprise him.
“My biggest concern is not him as a footballer but getting used to the Premier League, the speed and competitiveness compared to Italy or Portugal,” said the Hammers boss.
“His ability as a footballer is not in question, he’s proved it, and I just hope he can hit the ground running. That’s my only concern.”
Moyes admits he needed extra creativity in midfield, with Marko Arnautovic and Manuel Lanzini both suffering injuries of late.
Andy Carroll, Michael Antonio and Diafra Sakho are also on the sidelines and Moyes is not expecting to make a number of signings.
He added: “I would like to have a few more but the truth is I wouldn’t want to say because I couldn’t be confident we will get any more.
“At the moment I can’t say there is any guarantee there will be anybody else coming. It’s really difficult. Behind the scenes we have tried for two or three players and most of it is getting knocked back.”