Sunderland transfer targets Tommy Elphick and Ross McCormack have been left out of Aston Villa's squad for pre-season games in Germany.
Sunderland's Championship rivals have opted not to take the pair to Germany for a pre-season tournament, with Gary Gardner and Aaron Tshibola also left behind.
Striker McCormack had until now been a part of the pre-season programme but his future has now been thrown into fresh doubt.
Sunderland boss Simon Grayson is a fan of McCormack, who enjoyed a successful spell under the Black Cats boss while at Leeds United.
And the Echo understands that Sunderland have recently inquired about the availability of the striker, who endured a torrid first season at Villa Park following a big money move from Fulham.
McCormack had a very public falling out with manager Steve Bruce last season, and it had been thought the Villains £12million capture would be made available for transfer this summer.
Defender Elphick has also been strongly linked with a move to Birmingham City.
Elphick, who was signed last summer by former Villa boss Roberto Di Matteo, is expected to leave Villa Park this summer following the signing of John Terry.
The Black Cats will be in the market for another centre back should Lamine Kone leave the club as expected.
Elphick has an enormous amount of Football League experience, playing at Brighton for seven years before playing a key role in Bournemouth's rise to the Premier League.
It comes as Sunderland have also been linked with moves for Bournemouth striker Lewis Grabban, 29, and Cherries' 29-year-old Marc Wilson, who can play in defence or midfield.
Wilson has previously been linked with West Bromwich Albion.
Sunderland, who beat Bradford 3-2 at Valley Parade in their latest friendly, have so far added four players to their ranks with James Vaughan, Aiden McGeady, Tyias Browning and Brendan Galloway joining.