The winger made just three appearances for the Baggies after joining the club in the summer and will now head to the Netherlands on loan, but Clarke's side retain the option to buy
El Ghanassy joined the Baggies on loan from Belgian side AA Gent in the summer, but the 22-year-old has found first team opportunities hard to come by, being restricted to just three cup appearances.
Rather than send El Ghanassy back to his parent club however, West Brom have been given permission by the Belgian side to loan the winger to Heerenveen for the remainder of the current campaign, while retaining their option to purchase the Belgian permanently in the summer if suitably impressed.
Albion’s sporting and technical director Richard Garlick told the club’s official website: “Due to the team’s progress this season, Yassine has found first-team chances hard to come by.
“We feel it is in everyone’s best interests to allow Yassine to go out on loan and get some games under his belt.”
El Ghanassy, who is of dual Belgian-Moroccan nationality, started his career with La Louviere before joining AA Gent in 2008.
Having made his international debut for Belgium in a friendly against Finland back in 2010, he scored on his Baggies debut against Yeovil Town, before going on to make further appearances against Liverpool and Queens Park Rangers.