Blake Shelton is happy Christina Aguilera and Cee Lo Green are returning to 'The Voice USA'.

The duo - who were replaced by Usher and Shakira - will be welcomed back as coaches on the fifth season of the show after taking a short break to focus on their own music careers.

Blake said: ''Christina and Cee Lo were a part of helping build this thing. I never wanted to see them go.''

Producers have recruited the experienced mentors in the hope that the show - which, at 14.5 million viewers per episode in the US, is popular than ever - will be even more successful upon their return in Autumn.

A source told Us Weekly magazine: ''The show is in a great position right now. They want it to be stronger than ever when the old coaches return.''

The 'Gypsy' hitmaker - who recently announced she was leaving the talent show to focus on her family - and the 'Scream' singer, who is focusing on his eighth studio album, are reportedly set to return to the singing show next year.

As part of a rotating judging panel, both stars are said to be in negotiations with NBC to sign a deal for the 2014 spring season.