He has shown glimpses of his undoubted talent at times, producing a stunning drive to secure fourth spot in the Miami Sprint Race, while he also impressed during last weekend's Canadian Grand Prix, finishing eighth in testing conditions.
The 34-year-old, however, has been consistently outperformed by team-mate Yuki Tsunoda, who boasts a 7-2 record in qualifying, and has secured points in six of his last eight races.
'World-class talent' should have stayed at Red Bull
Ricciardo drove for Red Bull between 2014-2018, winning seven times whilst partnering former world champion Sebastian Vettel, as well as current title-holder Max Verstappen.
The Australian opted to leave the Milton Keynes-based outfit ahead of the 2019 season to embark on a new challenge at Renault, before moving on to endure an disappointing spell spell at McLaren.
Having been brought back into the F1 fold at RB following a short spell away from the sport in 2023, Ricciardo had ambitions of making a return to Red Bull.
That prospect looks increasingly unlikely to materialise now given the reigning constructors' champions decision to retain Sergio Perez for another season.
Writing in his Sky Sports column, Brundle reflected on Ricciardo's decision to leave Red Bull whilst at the top of his game, claiming that he 'never seemed to be quite the same driver' following that departure.
"Daniel has won eight GPs including an outstanding Monaco victory, scored 32 podiums, and has regularly shown world-class talent," he said.
"But those results were quite a while ago and I wish he'd not left Red Bull at the end of 2018. That was an emotional and flawed decision, he should have faced up to Max in the best car, then he'd have necessarily raised his game even further.
"Ricciardo never seemed to be quite the same driver again.
"He clearly still does have speed and race craft, as we witnessed also in the Miami Sprint, but something in his psyche or approach is holding that back and it's costing him opportunity and longevity."