Red Bull team principal has admitted that a number of teams could claw back the gap between his organisation and the rest of the field in 2024.
Last season was an historic one for Horner and co, winning 21 of the 22 races and taking the constructors' title at a canter.
With star driver Max Verstappen setting record after record, the Milton Keynes-based outfit were able to crush their opponents, finishing 451 points ahead of second-placed Mercedes.
However, Horner is certainly expecting more of a fight, suggesting that the fact his team were able to get out of the blocks so quickly when regulations changed in 2022 may lead to what he calls 'diminishing returns' in the next couple of seasons.
“I’m fully expecting with stable regulations, [there’ll be] diminishing returns for us, because I think we got to the top of the curve quicker than others,” he told F1.com.
“The field is going to converge. For us, it’s difficult to know who that will be. Will it be McLaren? Will it be Ferrari? Will it be Mercedes? It keeps moving around behind us. But that’s what we’re fully expecting going into [this] year.”