Chelsea striker Diego Costa may be prolific at club level, but Spain's coach Vicente del Bosque feels it is time he proves himself on the international stage as he leads the champions' attack during Euro 2016 qualifying.

Having convinced Costa to turn his back on Brazil, the country of his birth, Del Bosque has so far shown plenty of belief in the forward and gave him a chance to shine at this year's World Cup, but he and Spain failed badly.

I think that he can be very important for us as I believe in his qualities

Vicente del Bosque, Spain's coach

The team were unable to retain the trophy they won four years earlier, exiting at the group stage, and Costa was unable to score. He has now failed to register a goal in five games for the national team.

Costa will be the focal point in attack as a new look Spain, with veterans Xavi, Xabi Alonso and David Villa all having announced their international retirement, seek to win the European Championship for a third straight time.

Switch from Atletico

They face Slovakia on Thursday and Luxembourg on Sunday as they look to progress in qualifying Group C that also includes Macedonia, Ukraine and Belarus.

The 26-year-old striker came to the fore as he won La Liga with Atletico Madrid last season, notching up 36 goals, and has found no difficulty adapting to life at Chelsea, with nine in nine appearances so far.

"Diego has in front of him the challenge to show everyone that we have taken the right decision," Del Bosque told Spanish sports newspaper Marca.

"Maybe we are wrong, and it does happen in football, but I have a lot of confidence in him that he is going to do very well.

"I think that he can be very important for us as I believe in his qualities. He has put his faith in us and we have put ours in him.

"If I had seen anything that made me doubt him then I would say it."

Source: Reuters