The Premier League giants beat off competition from several clubs to sign the young winger from Uruguayan club Penarol on deadline day last summer.
He has been gradually introduced to English football through their Under-23s side and the teenage winger has impressed at that level.
But Manchester United want to see him play first-team football and have been open to loaning him out in the ongoing window.
And it has been claimed that the Red Devils have found a club who are keen to sign Pellistri on loan this month.
The Uruguayan is on the verge of agreeing on a deal to join a La Liga club on loan from Manchester United this month.
It is unclear whether the deal would be for the rest of the season or it would be a longer loan deal for Pellistri.
Manchester United look to be finalising the agreement that would see the winger move to Spain in the coming days.
The Premier League giants will want to see him play first-team football in Spain and prove himself away from Old Trafford for the time being.