Spain boss Vicente del Bosque believes that Manchester City striker Alvaro Negredo has "untapped potential".
Negredo opened the scoring in Tuesday's 2-0 win over Georgia, a result that secured the world and European champions a spot in next summer's World Cup.
The 28-year-old has scored 10 goals in 19 games for his country, but Del Bosque wants more from the former Sevilla forward.
"He is a forward who plays beneath the capacity that he has. He still has untapped potential," he told reporters at a press conference.
Del Bosque, meanwhile, is believed to be close to signing a contract extension with his country.