It didn't prevent his son from claiming an impressive Grand Chelem and 1-2 for his team as they dominated the weekend.
The former Formula 1 driver also said that the world champion team would 'explode' if Horner kept his job as team principal, before being seen meeting Mercedes team boss Toto Wolff as rumours around his son's future swirled.
Horner has recently been the subject of an internal investigation into accusations of alleged 'inappropriate behaviour', an investigation which cleared him of any wrongdoing.
The 50-year-old vehemently denies the claims, and has said that he is 'pleased' that the process surrounding his conduct is over.
Red Bull infighting
However, Verstappen senior's comments, and calls from rival F1 bosses for there to be an external investigation into the allegations, have brought the spotlight back onto Horner.
What's more, supposed 'leaked' messages allegedly sent by Horner were released during the Bahrain GP weekend, although they have not been confirmed to be in relation to the allegations.
Now, Verstappen junior has been asked to comment on his father's words about Horner, in the lead-up to the second race of the season in Saudi Arabia.
“I have not asked him that, but my dad is very outspoken and he is not a liar, that is for sure," he told media ahead of the weekend.
"My dad and I are very close. We call every day. I don’t see myself in F1 without them (his father and manager) by my side.”