The 20-year old Chelsea striker was loaned to Everton on deadline day but Allardyce, preparing for the home meeting with the Toffees on Saturday, said he wanted to lure the talented Belgian to Upton Park.
"I chased him all summer to be honest," said Allardyce. "But when it became the final day of the deadline we missed out and Everton managed to secure his position.
"We were more or less told he was going back (on loan) to West Brom. We tried, but didn't manage to clinch it."