Former Blues skipper Grant Leadbitter is reported to have turned down the chance to rejoin Town as well as possible moves to a number of other Championship clubs in order to return to his boyhood side Sunderland, currently third in League One.
According to the Northern Echo, the Blues, Stoke and Blackburn all made formal approaches for the 33-year-old offering a bigger wage than the Black Cats.
However, Leadbitter, who joined Town from hometown club Sunderland for £2.65 million in September 2009 before departing for Teesside on a free transfer in May 2012, turned down all interest aside from the Wearsiders'. The move is expected to be concluded before the weekend.
The midfielder is out of contract in the summer and has made only two Championship appearances this season, both back in August.
"He’s a Sunderland lad, and it’d be a wonderful move for him,” Boro boss Tony Pulis said.
"Grant has a lot of affection for Sunderland, as he does with this club.
"We'll do anything we can. But the finances are out of my hands, they’re between both parties.”
Speaking early on in the transfer window Town boss Paul Lambert poured cold water on reports that the Blues were after Leadbitter and Teessiders team-mate Rudy Gestede.
"Well, if somebody’s going to drop a massive nest egg of money in here then you might look at it, but I don’t think that’s going to happen,” he said.
The Black Cats are also reported to have made a £2 million offer to Barnsley for former Blues striker Kieffer Moore, who has scored 15 goals this season.
Moore joined the Tykes from Town for £750,000 in January last year with the Blues believed to be entitled to a 10 per cent of the profit the South Yorkshiremen would make on a sale.
Elsewhere, Portsmouth boss Kenny Jackett has played down the chances of ex-Town defender Matt Clarke moving on in the transfer window despite claims Stoke were readying a £6 million offer.
"First off, we’re not interested in selling him,” he said. "Secondly, we’ve not had an enquiry or a bid. But we’re not interested in selling Matt Clarke.
"We’re not interested, that’s the case. It’s not anything we’d entertain. There’s seven days left. But there’s been no enquiry or bid anyway. Even if there is, it won’t change the stance of the club - he’s not for sale.”
Clarke, 22, joined Pompey from Town in the deal which saw Adam Webster move in the opposite direction in June 2016. The centre-half is understood to have been valued at £50,000 in that deal, which was worth a total of £750,000, and that the Blues will receive 20 per cent of the profit the League One leaders make if and when he is sold.
Former left-back Tyrone Mings has been linked with a loan move back to the Championship from AFC Bournemouth with Derby, Aston Villa, West Bromwich Albion, Leeds United and Nottingham Forest all said to be interested.
Derby and West Brom are said to be the favourites for the 25-year-old, who left Portman Road for Dean Court in the summer of 2015 for an initial £8 million.