The Voice's spring episodes will see Shakira and Usher joining Shelton and Adam Levine on the judging panel as replacements for Christina Aguilera and Cee Lo Green.
Shelton recently admitted that the pressure to repeat Team Blake's season three win is already mounting.
"I would say the competitiveness is up. We've replaced Cee Lo with somebody that's just that much more aggressive [in Usher]," the country music star joked, according to Rolling Stone.
He went on to say: "Christina was always competitive, [but] now you've got four that are just killers up here."
Shakira concurred with Shelton's comment about increased competitiveness on The Voice, stressing that she and Usher are determined to win.
"There's a lot of competitiveness, of course," she said. "Once we are in the process of trying to get a contestant recruited for our team, there's a lot of adrenalin, and there's a lot of tension, but the healthy kind."
Shelton previously suggested that Usher and Shakira bring a different "chemistry" to The Voice.
"The show is still really good. It's still entertaining - it's just different personalities," he explained.
The Voice premieres its fourth season in March on NBC.
Watch Shakira and Usher's first commercial for The Voice below: