Marcus Rashford has shown in training that he has all the tools to become one of the world’s best players but the forward must improve his numbers on the pitch if he is to live up to his potential, England coach Thomas Tuchel said.

Rashford moved to Barcelona on loan in July after falling out of favour with Manchester United coach Ruben Amorim, who had called his work rate into question.

The 27-year-old, who has 18 goals in 64 appearances for England, has had a promising start to life in Spain, scoring three goals and registering five assists in 10 appearances.

“The limit for him is very, very high. Maybe higher than for others,” Tuchel told reporters on Monday. “He has the potential, but potential is a dangerous word with high-level sports. You have to reach your personal best on a regular basis.

“It’s not a question of talent, it’s a question of whether he can prove the point at club and international level … He can be one of the best in the world. The quality I see in training, the finishing with both legs and with the head.

“He is explosive, he is fast, he is strong in the air so where are the limits? There are no limits, but the numbers don’t reach the potential. He needs to push himself into goal involvements.”

Group K leaders England play Latvia in a World Cup qualifier in Riga later on Tuesday, where a win would secure a place at next year’s finals in North America.