Louis van Gaal says Manchester United have offered David de Gea "a lot of money" in a bid to keep him at Old Trafford.
The 26-year-old forward has been at The Hawthorns since joining from Reading in what was a club-record deal in August 2011.
Long's time at Albion looked to be up in September when the club agreed a deal with Hull, only for the transfer-deadline day move to collapse.
Steve Bruce's side remain keen on the Republic of Ireland international, who was keen to play down any talk of a January departure despite his contract running out at the end of the season.
"All I know is that there are plenty of rumours," Long said.
"But no-one has said anything to me and unless something happens in the next couple of weeks I am just concentrating on giving everything to West Brom."
Long has put in a number of impressive performances for the Baggies since his move to the KC Stadium fell through.
The Irishman again proved a handful in Saturday's 1-0 defeat at Southampton - a match they would have left with a point had Artur Boruc not impressively saved the forward's last-gasp strike.
"We did not play as well as we can for 60 to 65 minutes and it took their goal to kick us into action," Long said.
"We created plenty of openings in the last 10 minutes and I will never know how the goalkeeper kept out my shot in the last couple of minutes."
Had Long's shot found the net rather than Southampton's Polish goalkeeper, caretaker boss Keith Downing would be handing over the managerial reins unbeaten in his five league matches at the helm.
The assistant head coach steadied the ship after Steve Clarke's departure and will now form part of Pepe Mel's backroom staff.
The former Real Betis manager watched from the stands at St Mary's and Long was sorry not to maintain Downing's impressive record in charge.
"Keith Downing and Dean Kiely did a great job in a short time," he said.
"They took over when confidence was low.
"We knew we had the players but we had not been playing well and in fairness to him he got it out of us.
"It would have been nice to have ended his spell with a win to thank him for his efforts.
"It was a frustrating match for us."