While Bumrah has been ruled out because of a stress fracture, Rahul has been dropped for the three-match Test series owing to his poor form with the bat.
"He (Bumrah) is a phenomenal talent and I've had the privilege and opportunity to play with him even before he had the opportunity to play for his country. We played on the same junior level team and he's always someone that's very determined and dedicated and very passionate about cricket, and he's someone you don't want to mess with because he bowls the ball at serious speeds and he's a competitor off the field even when we are playing against each other.
"There's no mercy for the guys who play for the country -- he's always very competitive. The things that he's doing for the country right now is absolutely fantastic and I know he's only going to grow and get better," Rahul said during a Red Bull interaction.
The 27-year-old also revealed how he would love to team up with England all-rounder Ben Stokes in the IPL.
"What he did was unbelievable. It will always remain the best Test match that was ever played. To play an innings like that is incredible," Rahul said.
"He (Stokes) can bowl, he's a phenomenal fielder, yeah, he's played out there before and he's had a great impact on the teams he's played for. I hope he can play for my team, it'd be great to have him in my team," said Rahul.
Rahul, who has played 36 Tests, 23 ODIs and 28 T20Is for India, also revealed that Australia's Pat Cummins is the toughest bowler he has played so far.
"I found him (Cummins) very hard to face. Rashid Khan has always got the edge over me -- he has my number a little bit. (There's) Nathan Lyon from Australia (also). All these guys and Bumrah of course," he added.