Britney Griner had a stern message for Caitlin Clark ahead of her WNBA debut with the Indiana Fever.

‘You’re going up against grown women,’ Griner told People, when asked to describe what the 22-year-old rookie will face in the league.

‘This is how they feed their families. This is not just for the love of the [game]. This is their livelihood.’

The Phoenix Mercury star admitted she had a difficult transition from Baylor University to the pros after she was drafted number one overall during the 2013 WNBA draft.

‘It’s different, when you come from college to the pros. I went from top dog to my numbers going down a bit,’ she recalled, describing her rookie season an ‘eye-opener.’

Britney Griner sent a warning to Caitlin Clark before hotly-anticipated WNBA debut

‘You’re going up against grown women,’ Griner said, when asked what Clark will face

‘I had to get stronger, lock in a little more. There will be some growing [pains] for her, but she’ll be fine,’ the two-time Olympic gold medalist said of the Iowa alum.

Clark and Griner could meet on court for the first time when the Fever play the Mercury on June 30.

However, there’s a chance the two may already be teammates by that time should they both be selected for the Team USA squad, which will be finalized in early summer.

‘This is how they feed their families. This is their livelihood,’ the Olympian added

Clark made her home debut for the Indiana Fever on Thursday, less than a month after the draft

‘I used to say I’d play until the wheels fell off,’ Griner went on. ‘But when I can’t produce the way I want to produce, I’ll hang it up. I don’t want to push the envelope or hold back the team.’

Her comments came amid Clark’s highly-awaited home debut for the Fever Thursday night.

Nearly one month after she was selected by the team with the first pick in the WNBA Draft, she impressed her home fans with 12 points, eight rebounds, six assists, and a block in 32 minutes of play.

‘It was a lot of fun, I thought they were loud, I thought they were into it. It was fun to see,’ Clark told reporters after the game.

‘This is a preseason game on a Thursday night and there’s 13,000 people here,’ she said

Some teams are even moving their games to bigger venues amid Clark’s growing popularity

‘This is a preseason game on a Thursday night and there’s 13,000 people here,’ she continued. ‘I think that just shows you what it’s going to be like for us all season. It’s going to help us.’

Some of the Fever’s opponents have even started moving their games to larger venues to accommodate ticket sales, amid the curiosity surrounding Clark.

‘For me, this is the best part of it,’ she said. ‘You’ve got to go out and compete every single night and if one night is not good for us, you have an opportunity to come back a couple days later and respond … everybody’s excited.’

Clark will play her first regular season game with the Indiana Fever next week.