Inter Milan midfielder Joao Mario is set to become West Ham United's first signing of the January transfer window after David Moyes confirmed that the midfielder was undergoing a medical ahead of completing a loan move until the end of the campaign.

The Hammers have been linked with a number of midfielders in recent weeks including Anderlecht's Leander Dendoncker and Barcelona's Andre Gomez after it was reported that they failed to agree terms with Mario.

"Your sources would be correct," Moyes said during his pre-match press conference on Thursday (25 January), as quoted on the Hammers' official site. "I'm not going to tell you any more until he has done his medical. Once we have got the medical out of the way, I think we'll be able to tell you what he will bring to the side, so hopefully we'll be able to give you some more news at the right time. It would be a loan move."

The 25-year-old Portuguese midfielder joined Inter from Benfica in the summer of 2016. Mario impressed his debut campaign, but has struggled for regular game time under Luciano Spalletti this season.

The Portugal international was linked with a move to Manchester United at the start of the January transfer window. He was touted be part of a swap deal that involved Henrikh Mkhitaryan moving to the San Siro.

The latter eventually moved to the Emirates Stadium to join Arsenal as part of a swap deal that saw Alexis Sanchez join the Old Trafford outfit. Mario will spend the rest of the campaign at the Olympic Stadium with reports suggesting that West Ham have an option to make the deal permanent at the end of the season if they meet Inter's £26m ($37.1m) valuation.

Moyes is certain to be elated at the capture of the Portuguese midfielder, who can play through the middle or on the right flank. But the manager does have a slight concern about the midfielder's ability to adapt to the Premier League in the short space of time.

The former United boss is hoping that Mario can hit the ground running despite the vast difference between the English top-flight and the Serie A and the Portuguese League.

"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," the West Ham United boss said, as quoted by BBC Sport.

"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."

Joao Mario
Inter Milan's Joao Mario has completed a loan move to West Ham United Getty