Harris, the current first choice for the Test side, has been frozen out at Wilderspool since being transfer-listed at a world record pounds 1.3m last season.
He has been training on his own while Warrington and prospective buyers, St Helens, have drifted further and further apart in their negotiations.
But now Warrington have told him to come back to Wilderspool to train with their squad and Harris has accepted the approach.
A statement from the club said: "Iestyn Harris has been instructed to report back to the club for training. This is following the failure of St Helens to put forward anything like an acceptable proposal for his transfer.
"St Helens approached the player and unsettled him at a crucial time for the club and the loss of his goal-kicking may well have cost the club fourth place in Super League.
"Iestyn is no longer available to St Helens - contact between them is prohibited - but he is still on the transfer list."
A spokesman for Harris said he had always been willing to continue to play for Warrington but still wanted a move.
Saints have confirmed that they will appeal against Bobbie Goulding's eight-match ban for his high tackle on Wigan's Neil Cowie in the Challenge Cup tie last Saturday.
"It is five years since Bobbie was last sent off and we feel the severity of the sentence outweighs the severity of the offence," David Howes, the club's chief executive, said.
Saints and Wigan have each been fined pounds 15,000 for their televised brawl in the wake of Goulding's tackle. Half the fine has been suspended for a year in each case but the clubs, who have been told they have no right of appeal, are to seek legal advice.
Carlisle and the amateurs, Dudley Hill, who were also involved in a brawl in their tie last weekend, have each been fined pounds 1,000, of which pounds 750 is suspended.
Halifax have signed another young French player, the 18-year-old second- rower, Jerome Guisset, from St Esteve.
First and Second Division clubs knocked out of the Challenge Cup last weekend play in the first round of the new Silk Cut Plate competition tomorrow.Reuse content