In the meantime, here's every signing the Black Cats have made in January over the last decade, and a look at where they are now.
1. Matt Kilgallon - January 2010
After failing to break into the Black Cats' first team, the ex-England U21 international went on to join Blackburn in 2014. He's now plying his trade for Indian side Hyderabad FC. (Photo credit: LINDSEY PARNABY/AFP via Getty Images) Photo: AFP
2. Stephane Sessegnon - January 2011
Costing £6m from Nice, The Benin international excelled for three seasons in the top tier with Sunderland. He's now with Turkish outfit Genclerbirligi S.K., and has been one of their star players this season. (Photo credit: OZAN KOSE/AFP via Getty Images) Photo: OZAN KOSE
3. Alfred N'Diaye - January 2013
The centre-back never really got going for the Black Cats, and has continued to bounce between clubs since leaving a year later. He's currently playing Saudi Arabia for Al-Shabab. (Photo credit: ANNE-CHRISTINE POUJOULAT/AFP via Getty Images) Photo: ANNE-CHRISTINE POUJOULAT
4. Danny Graham - January 2013
The former Middlesbrough man scored just once in his time at the Stadium of Light, and eventually joined Blackburn Rovers following a successful loan spell. Graham is still there, and netted 16 goals for them last season. (Photo by Lewis Storey/Getty Images) Photo: Lewis Storey