Ivory Coast international striker Lacina Traore is set for a medical at Everton ahead of a proposed loan move from Monaco.
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The 6ft 8in forward had been set to join West Ham, who successfully applied for a work permit on his behalf.
But the Hammers reportedly stalled on completing the deal because they had concerns over a hamstring injury Traore suffered last month.
Sources have told ESPN that Everton want to discover how serious that injury is before committing themselves to a move.
Everton manager Roberto Martinez said on Friday that signing a striker was a priority following the sale of Nikica Jelavic to Hull.
But the move for Monaco forward Traore has frustrated West Ham manager Sam Allardyce, who feels his original bid to sign him has been hijacked.
Allardyce told the Daily Mail: “After doing a deal with them, Monaco didn’t sign the paperwork off when we asked them to on the basis that they said someone else is now interested.
“We wouldn’t have gone to all the trouble of a work permit and visiting him out there and doing his medical if we had known that. But sadly it looks like at the 11th hour there’s been a change of heart.
“Of course when you’ve worked so hard for a top-quality player like him, it’s a real kick in the nuts.”
Traore has been made available for loan by Monaco, even though they only signed him on January 4 from Russian Premier League club Anzhi Makhachkala on a four-and-a-half-year contract.
Monaco boss Claudio Ranieri sees the 23-year-old as a long-term signing, with Radamel Falcao the club’s first-choice striker for now.
Traore attracted the attention of football fans on Merseyside when he scored for Anzhi as they beat Liverpool 1-0 in a Europa League group stage game on November 8, 2012.