Midfielders Carlos Edwards and Grant Leadbitter have joined Championship side Ipswich Town in a combined deal.
Sunderland will bank up to £2.6m from the sale of Leadbitter and a potential further £1.35m for Edwards.
The pair will link up with former Sunderland manager Roy Keane, as the Irishman looks to strengthen his squad who have so far struggled to make an impact on the Championship this season.
Sunderland-born Leadbitter, who flourished during Keane's reign at Sunderland, will leave Sunderland after making the progression from the club's youth system and regularly featuring in Sunderland's starting line-up since his league debut against Charlton in December 2005.
His initial club debut was in League Cup action against Huddersfield Town in September 2003.
Edwards was brought to Sunderland by Keane from Luton Town, in the January transfer window of the 2006/07 campaign, to bolster attacking options as they pushed for promotion from the Championship.
The Trinidadian winger was an instant hit on Wearside as the the team were promoted to the Barclays Premier League as Champions, and will be remembered by fans for his screamer against Burnley in the 3-2 victory at the Stadium of Light during the 2006/07 campaign, that edged the Black Cats closer to sealing promotion.
However, Edwards failed to make an impact in the top flight the following season and spent time at Wolves on-loan in 2008.
Both players featured in Sunderland's Carling Cup win over Norwich last week, whilst Leadbitter replaced an injured Lee Cattermole during Sunderland's home defeat at Chelsea earlier this season.
Edwards and Leadbitter follow Danny Collins out of the Stadium of Light exit door today, as the sumer transfer window is set to slam shut at 5pm.