The Japanese driver currently holds a 7-2 lead over the Australian in qualifying, and has scored points for his team in five the last seven races.
Ricciardo, meanwhile, only secured his first grand prix points of the year in Canada last weekend, though he showed glimpses of his talent at the Miami Sprint Race, producing a stunning drive to finish fourth.
Australian under pressure to pick up performances
The eight-time race winner previously had one eye on making a stunning return to Red Bull in the future, but now faces a fight for his F1 future, and has been on the receiving end of much criticism in 2024, with former world champion Jacques Villenueve the latest to slam the 34-year-old.
With Tsunoda signing a new deal until the end of next season, and RB reserve driver Liam Lawson waiting in the wings for an opportunity, Ricciardo is under pressure to prove he still has what it takes to deliver results at the top level.
F1 pundit Andrew Benson believes Ricciardo still has the backing of his former boss Horner, which goes a long way towards explaining why he has yet to be dropped despite his lacklustre showings.
Writing in his BBC column, Benson said: “Ricciardo is 7-2 down on Tsunoda in grand prix qualifying sessions this year and slightly slower on average. And the problem with that is that Red Bull don't rate the Japanese as a top-line driver.
“This is why Ricciardo has gone from being considered a potential replacement for Sergio Perez in the main Red Bull team, to being at risk of losing his seat.
“Reserve driver Liam Lawson is waiting in the wings. But Ricciardo is currently protected by team principal Christian Horner. It remains to be seen which way Red Bull go in choosing a partner for Tsunoda at what is now called RB in 2025.”