The swoop is subject to the marksman passing a medical on Wednesday afternoon, and if that is successful, he could make his debut in Sunday's Worthington Cup final against Tottenham.
"I would describe him as an 'English-style' striker," Rovers boss Graeme Souness told the club's official site.
"There is much to be sorted out yet, but I am hoping to sign him on a loan arrangement until the end of the season."
Souness has been active in the transfer market of late as he seeks to prevent the club making a swift return to the First Division.
He made Andy Cole the club's record signing in December and is also in negotiations to bring Galatasaray defender Hakan Unsal to Ewood Park.
Scoring goals has been Blackburn's downfall and with Yordi expected to link-up with Cole in the Rovers attack, they will have experienced firepower to boost their survival hopes.
The 27-year-old Yordi has netted six goals in La Liga this season and Rovers will have the option to purchase him, if he proves to be a hit at Ewood Park.
