Middlesbrough manager Garry Monk has insisted that defender Ben Gibson will not be sold this summer unless the club receives "an extraordinary offer".
The 24-year-old has been heavily pursued by West Bromwich Albion since Boro's relegation from the Premier League, with manager Tony Pulis recently describing him as "a smashing player".
The Baggies were thought to have had a bid of £18m, with £3m in add-ons, rejected last month as Boro look to bounce back to the top flight at the first time of asking.
"From day one, it was very clear we don't have to sell any player," Monk, who took over at the Riverside in June, told reporters.
"I said all along it would have to be an extraordinary offer for any player to leave and we don't want our important players to leave.
"We are clear on that. We have not given it a second thought.
"He is fine, training well, determined and has this club in his heart, looking forward to the season ahead."
Gibson - nephew of Boro chairman Steve Gibson - has been with the club since the age of 12.