Mexican Sergio Perez named compatriot Esteban Gutierrez as his 2013 replacement at Sauber despite no formal news from the Swiss Formula One team.
Sauber have announced the arrival of Germany's Nico Hulkenberg from Force India but have kept quiet about who will be his team mate, saying only that confirmation would come within the season.
However Perez, who is joining McLaren, appeared to spill the beans in a conversation with Spanish-speaking reporters at the season-ending Brazilian Grand Prix.
"The car will be strong because the rules don't change much, and the team have a good experienced driver in Nico and he will have a strong team mate in Esteban," he said.
"We are waiting for the announcement," he added when asked for more details.
Gutierrez's promotion from a test and reserve role -- widely expected given the team's Mexican sponsors -- would mean the departure of Kamui Kobayashi, the only Japanese driver on the grid.
Perez is moving to McLaren as replacement for 2008 champion Lewis Hamilton, who will race for Mercedes as the most high-profile signing for 2013.
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