London - Sergio Perez's seat with Red Bull is safe for this Formula One season, former champion Jenson Button said on Tuesday, but if the Mexican's struggles continue he could be looking for another team next year.
Perez was in the thick of the championship hunt just a month ago but has suffered a dramatic dip in performance with a run of sub-par results, failing to reach the podium in the last three races for dominant Red Bull.
Team mate Max Verstappen claimed his sixth win of the campaign at the Canadian Grand Prix on Sunday to open a 69 point lead over Perez in the standings, with Aston Martin's Fernando Alonso closing in on second and now just nine adrift.
Concern has mounted to the point that Red Bull team principal Christian Horner felt the need to have a chat with Perez in Montreal, telling him to forget about the championship and refocus on driving.
Horner also said the team was going to stand by Perez and help him through the slump but Red Bull have not always shown patience with under-performing drivers.
"I don't think he is (in danger) for this year but at the end of the year who knows," said Button during a media call to promote NASCAR's first street race in two weeks' time in Chicago that the Briton will compete in. "Who do you put in there?
"Obviously they have Daniel Ricciardo there as an ambassador but I don't know if they are willing to put him in that seat.
"I've got to feel for Checo, three races on the bounce he's been below par.
"There's no catching Max now he's gone and the championship is definitely his."
Scenarios are starting to emerge about what a possible drivers shake-up at Red Bull might look like.
One rumour has Ricciardo, who previously drove for Red Bull from 2014-18, going from a reserve role to a seat with sister outfit AlphaTauri, replacing under-performing Nick de Vries.
Such a move would allow Australian Ricciardo to remove some competitive rust and make a seamless transition back into the Red Bull seat if Perez was dumped.
"Do they take someone from AlphaTauri?," questioned Button. "If so who would it be - De Vries or would you put (Yuki) Tsunoda in the A Team."
Button also said he will be back full-time racing next year.
The 43-year-old is scheduled to drive in three NASCAR Cup races this season, including Chicago, and two weeks ago was part of the driver lineup for NASCAR's Garage 56 entry at the Le Mans 24 Hours.
Button would not say what team or series he will compete in other than that it will be endurance racing in either the International Motor Sports Association (IMSA) or the World Endurance Championship (WEC).
"I will be racing in something next year doing a full season," said Button. "I want to do a full season next year and time permitting it will be endurance racing."