The lively forward's form has put him on the fringes of a call-up to the full Spanish side after he grabbed his second hat-trick for the U21s against Estonia earlier this month, making it seven in four games for them.
While Wanderers supporters may raise a few eyebrows at the meteoric rise of a player who shone so briefly in the Premier League, Coyle has not been surprised.
"He's such a huge talent," the Scot told the Bolton News. "People forget that in football terms he was a baby when he came to this club last year. The bits and pieces you saw were great, especially considering he was adjusting to a new culture and new surroundings.
"Had we got him back, I've got absolutely no doubt he would have been sensational, more from a starting position as well."