Premier League - Black Cats go for United trio
Press Association Sport understands the Black Cats have tabled a joint offer amounting to in excess of £12million for defender Wes Brown, midfielder Darron Gibson and a third member of Sir Alex Ferguson's first-team squad.
The move came as Henderson's £20million switch to Anfield edged closer to completion. England international Brown, 31, was at one stage earlier in his career touted as the new Bobby Moore, but a succession of injury problems has hampered his progress in recent years.
Gibson too has had to remain patient as he seeks a regular place in United's star-studded midfield, and the 23-year-old's Republic of Ireland boss, Giovanni Trapattoni, has on more than one occasion suggested he might benefit from a move to a club where he would play every week.
Sunderland have been quick to press home their interest in the trio less than 24 hours after reaching agreement with Liverpool over Henderson.
Chairman Niall Quinn said: "We know the areas that need strengthening and the type of player we need in order to progress, and the job of bringing those players to the club is continuing at a pace."