Sky Sports sources understand Sunderland defender Nyron Nosworthy will join Sheffield United in preference to Portsmouth.
Nosworthy is expected to leave the Stadium of Light before the 5pm deadline, with manager Steve Bruce happy to let the 29-year-old head out on loan.
With Bruce having signed Matt Kilgallon from Sheffield United, and also targeting a new right-back, Nosworthy could find his opportunities limited in the second half of the campaign.
He has made just 10 Premier League appearances this season and has attracted plenty of interest from other clubs in recent weeks.
West Brom and Wolves are among the teams to have weighed up a swoop for Nosworthy, but it appears the former Gillingham man will be heading to Bramall Lane.
Portsmouth are understood to have shown a desire to sign Nosworthy, but the player has opted to help the Blades' bid for promotion to the top flight.
His versatility will also come as a major boost to Kevin Blackwell, who has been trying to sign a centre-back and left-back before the close of the transfer window.
Blackwell, who lost Kilgallon to Sunderland, also has several injuries to contend with and the addition of Nosworthy will ease his problems at the back.