Christian Horner has raised the possibility of Sebastian Vettel taking a sabbatical from Formula One.
Four-time world champion Vettel, who is being moved on by Ferrari at the end of the current campaign, is 13th in the standings following an unsatisfactory streak of results.
Vettel, 33, has been linked with a move to Racing Point in 2021 but Sergio Perez and Lance Stroll, the son of the team's co-owner Lawrence Stroll, are under contract for next year.
"It is a shame because Sebastian is obviously not in a happy place," Horner, who oversaw Vettel's four consecutive titles as Red Bull team principal, told the PA news agency.
"He is still relatively young, so it depends what his motivation is, but he is a four-time world champion and the third most successful driver of all time in terms of his victories. Nobody can take that away from him.
"If he chose to take a year out, he would still be very attractive to teams should he wish to come back in 12 months' time.
"He doesn't need to be in Formula One for the sake of being there next year. What he has achieved in this sport is quite phenomenal and I am sure he is thinking hard about his next move. He is carrying a lot of weight on his shoulders at the moment and that must be very tough for him."
Vettel's star shone at Red Bull before he turned his back on the team to join Ferrari for the 2015 campaign.
Max Verstappen has since replaced Vettel as Red Bull's main man and the Dutchman heads into Sunday's Spanish Grand Prix as the closest championship challenger to Lewis Hamilton.
Verstappen, 30 points behind Hamilton, delivered a fine victory at last weekend's 70th Anniversary Grand Prix to end Mercedes' winning streak and raise the prospect of a mouth-watering title fight.
"For Formula One it would be fantastic because everybody is dying for that rivalry to erupt," added Horner. "Max and Lewis are the two standout drivers in Formula One at the moment.
"Both are at different stages of their careers and it would be great to see them go head-to-head, this year and next.
"When people know what the result is going to be, why bother watching, unless you are a die-hard fan? Sport is all about competition and that is what we want to see.
"So hopefully we can be competitive with Mercedes and have more Sundays like last Sunday and get ourselves back into the championship fight."
