Swansea City’s owners say they will “not be bullied” into selling midfielder Gylfi Sigurdsson below their £50m asking price.
Swansea have reportedly rejected £40m bids from Everton and Leicester.
American owners Steve Kaplan and Jason Levien said: “We will not be bullied or forced into a decision until a club meets our valuation of the player.”
Sigurdsson, who has three years left on his contract, did not travel to the US for the Swans’ pre-season tour.
Kaplan and Levien also warned any clubs interested in Sigurdsson against believing they have a deal with him.
“Any such agreement would obviously be in contravention of Premier League legislation,” they added.
Both owners also hope the player will rejoin his team-mates in their pre-season preparations.
“We have the ultimate respect for Gylfi as a person and a player and we are optimistic that he will reconsider his decision and join his team-mates,” said the American businessmen.
Sigurdsson’s absence from the trip to America was announced on Thursday.
“Gylfi did not feel in the right frame of mind to travel due to the current uncertainty over his future,” said the Swans on Twitter.
Manager Paul Clement has said the “business side to football” meant the club might have to sell him.
“I’ve made it very clear I want him to stay here,” he added.
“He’s one of our most valuable players. He showed that last season with his goals and his assists, and he was instrumental in us maintaining our Premier League status.”