Senator Alan Peter Cayetano and Senator Ferdinand "Bongbong" Marcos Jr.

DAVAO CITY - Senator Alan Peter Cayetano labelled losing candidate Ferdinand "Bongbong" Marcos Jr.'s claim that a Cabinet post will be given to him after the mandatory year-long appointment ban as mere "speculation."

Cayetano noted that President-elect Rodrigo Duterte is keen on getting only "the best and the brightest," and that Marcos does not fall under those descriptions.

"Would I go against him (Marcos) if I think he's among the best and the brightest?" Cayetano told reporters here on Sunday.

"I haven't heard that there was a formal offer," he added.

(READ: Bongbong open to Duterte Cabinet post)

On Saturday, Marcos said he is willing to serve as a Cabinet secretary under the Duterte administration.

"The details have not yet been ironed out. If given a chance, it would be an honor," the outgoing senator said.

Despite his sour relations with Marcos, Duterte's former running mate admitted that it's still the President-elect's "prerogative to appoint whoever he likes."

"I may like some of his appointments, I may not like the other appointments, but I believe in him (Duterte) and support him all the way," Cayetano said.

Cayetano, who has been trailing Duterte in Davao and Cebu since the #DU31 Thanksgiving Party, said it's too early to say what's going to happen in a year's time.

Cayetano said the 71-year-old firebrand can change his mind on appointments, including his initial decision not to give a Cabinet post to Vice President-elect Leni Robredo.

(READ: Duterte: No Cabinet post for Leni Robredo)