Argentina striker Hernan Crespo, who spent last season on loan at AC Milan, is to resume his career at Chelsea.
"We're delighted Hernan is coming back," Chelsea chief executive Peter Kenyon told the club's website on Wednesday.
"He had a great season on loan at Milan and showed what a good player he is. He is very happy to be coming back to Stamford Bridge and I know he will be welcomed by everyone."
The Premier League champions began pre-season training on Wednesday but Crespo's return will be delayed until Monday because the Serie A season finished later.
The 30-year-old, who played for Parma, Lazio and Inter Milan before joining Chelsea in 2003, got 18 goals in all competitions last season for AC Milan, including two in the Champions League final which they lost on penalties to Liverpool.
Crespo joined Chelsea from Inter for a transfer fee of 16.8 million pounds ($29.45 million) and scored 12 goals in 21 starts and 10 substitute appearances for the London club in 2003-04.