LONDON (AFP) - Spanish Euro and World Cup winning striker Fernando Torres pledged on Saturday to try his heart out to regain the form that saw him become one of the most feared marksmen in world football.

The 29-year-old - capped over 100 times by his country - has failed to replicate the form for Chelsea that earned him a £50 million move in January 2011 from Liverpool.

However, a brace against Russian side Rubin Kazan on Thursday in their Europa League quarter-final first leg took him to 18 goals for the season and gave him hope that he is on the right track.

"I want to do the things I used to do all my life," he told the Daily Mail. "I did them at Atletico Madrid, I did them at Liverpool and I am not doing them at Chelsea. I am working on it. If I knew the reason, I would fix it in one minute. But the only way to fix these things is to work at it.

"I am training every day and I will never, ever give up."

Torres, who scored 65 goals for Liverpool in 91 league starts, said that he was enjoying being at Chelsea and hoped he could propel them to the FA Cup and Europa League trophies, and hence salvage something from a generally disappointing season.