Luke Bryan has joked that Carrie Underwood will need to "up her therapist" after joining 'American Idol'

Asked what advice he has for Carrie, the 48-year-old star said in a TikTok video: "Up her therapist. If she has a therapist, she's probably going to have to double to deal with me and Lionel."

Luke subsequently joked that he was happy to assist his new co-star.

Luke quipped: "Do therapists do gift cards where I can call her therapist and gift her a voucher?"

Carrie won the fourth season of 'American Idol' back in 2005, and the singer recently revealed that she's looking forward to making her return as a judge.

In an announcement video, Carrie said: "I went from nobody knowing my name to tens of million of people watching the show.

"I'm proud of everything that I was able to accomplish on the show and I'm so proud of everything I've accomplished since."

Meanwhile, a source recently suggested that Carrie "couldn't say no" to 'American Idol'.

The award-winning star feels like she owed a debt of gratitude to the show, after first finding fame on the platform.

A source told DailyMail.com: "They have asked Carrie in the past to be a judge and either timing, money or other commitments have got in the way to make it a reality.

"She has been asked to coach on 'The Voice' as well, but it just never seemed right.

"Even with the opening she has to speak to the same people at NBC by working with 'Sunday Night Football', she has always felt that she needed to be loyal to 'American Idol'.

"She has always monitored the show that started her career, and now she couldn't say no."