Clearout begins at Sheffield Wednesday as Irvine plots instant return
Manager Alan Irvine has also released striker Leon Clarke, defender Frank Simek, and midfield duo Sean McAllister and Etienne Esajas.
The Owls were condemned to the drop after failing to beat Crystal Palace at home last weekend.
Irvine immediately vowed to shake up his squad and the departure of the 'surplus six' will release money for a string of new signings this summer.
"I would like to wish those players released the best of luck for the future," said Irvine. "I am sure that most, if not all, of them will find clubs.
"But I feel that we need to take the opportunity to rebuild our squad as we look to achieve promotion at the first time of asking.
"This summer gives us the opportunity to introduce the new faces that the squad needs to bounce back following relegation to League One," he added.
"Our recruitment process has already started and I can promise Sheffield Wednesday supporters that we will leave nothing to chance as we look to bring in exactly the right kind of players that will help us gain the promotion we need."
Jeffers, pictured below, and Gray were among the highest earning players at Hillsborough yet were unable to command a regular place in Irvine's side.
Striker Jeffers, who once cost Arsenal 8m, started only 33 games during his three-year stay but was hampered by injuries and transfer listed after being sent off this season for violent conduct in the Carling Cup.
Former Sunderland and Blackburn Rovers defender Gray, 35, signed a one-year deal last summer after impressing on loan from Wolves. He had been a regular prior to the departure of former manager Brian Laws.
Norwich City and Bristol City have already been linked with striker Clarke who signed off with a goal against Palace last weekend before getting injured during his goal celebration.
Simek's departure comes after a lengthy battle to return to full fitness following ankle surgery. The USA international, still only 25, joined the Owls five years ago after being released by Arsenal and, at one stage, was linked with a return to the Premier League.
Midfielder McAllister, 22, came through the ranks at Hillsborough and made over 70 appearances but dropped down the pecking order this season.
Dutch winger Esajas, 25, is another player who has suffered more than his fair share of bad luck with injuries.
Significantly, Irvine has offered new two-year deals to both reserve team goalkeeper Richard O'Donnell and third choice Arron Jameson.
With speculation surrounding the future of first choice Lee Grant, Irvine may yet view O'Donnell as a potential replacement.
O'Donnell – a product of the club's Academy – has yet to play for the Owls at first team level but has been out on loan with Oldham Athletic, Rotherham United and York City.
The Sheffield Wednesday Supporters Society, Wednesdayite, have requested a meeting with club officials over the impact of relegation.
The group, who also control the second biggest shareholding in the club, want to know more about the club's plans to bounce back and how they can help.
"There is little point now in finger pointing or apportioning blame," said a spokesman. "There is no point at all in throwing our hands in the air and giving up.
"As a fans group, we will be seeking meetings with the leaders at the club to discuss ways in which we can play a part in the development process. As the second largest shareholder in the club, we will be asking the SWFC board what actions they are taking, individually and collectively to help to achieve success."
Chairman Lee Strafford, meanwhile, will be holding meetings with all the club's potential investors in the next few weeks to assert how relegation impacts on their interest.
"We'll be focussing on investor discussions this week and in following weeks," he said. "We go back to them and say 'that's the uncertainty (over the club's league status) gone, do you still want to do the deal?'"
Wednesdayite also issued a statement condemning the behaviour of those involved in the pitch invasion at Hillsborough following Sunday's draw against Palace.
Eight people were arrested and released on bail for public order offences but police and club officials are still studying video footage which may lead to further action.
"What we saw from those who invaded the pitch was nothing at all to do with passion or support for the Owls. It was mindless, unthinking and unacceptable behaviour," said the statement.
"As a result, we might all suffer from the consequences of the action of a small group who do not deserve to be referred to as Wednesdayites."