The West Ham united player appears to be close to a permanent exit.
The report claims West Ham will receive £5million for the 30-year-old and that once he has completed his medical he will travel straight out to Spain to link up with his new teammates.
Downing has been linked with the Upton Park exit for a while despite impressing in an attacking midfield role last season.
He was less effective when pushed back into a wide position and with Dimitri Payet arriving in London this summer it seems West Ham manager Slaven Bilic has decided he does not need Downing.
But if the Teesside Gazette is correct and this will be Downing’s last day as a West Ham player, the Hammers could live to regret the move considering the sheer number of games they will have to play in the coming months.
Their Europa League qualifying campaign means their season has started considerably earlier than any of their Premier League rivals, and as we have seen in the past, Europe’s secondary competition has a habit of taking it out of its earliest participants when the business-end of the campaign rolls around.
As for Middlesbrough, it seems they are on the verge of welcoming their former player back, and as Downing showed at times last season, he remains a potent goal-threat who should excel in the second tier.