Valentino Rossi says Yamaha has taken "a risk" by re-signing Jorge Lorenzo rather than replacing him with a clear number two rider, and that the Spaniard's new deal has made him question his long-term future with the team.
After a summer of frenzied speculation over Lorenzo's next move - which saw him strongly linked to both Honda and Ducati - he recently agreed a deal to remain alongside Rossi at Yamaha.
Rossi has now hinted that Lorenzo's continued presence could make him look elsewhere when his own contract expires next year, as he does not think pairing two potential title contenders is a good strategy.
"For sure I'll have to decide what to do in the future," said the reigning champion. "For quite a while the top teams have always had just one top rider, while Yamaha has two.
"This can certainly be good for Yamaha, because to have two quick riders is very important also for the constructors' championship, but it's certainly more risky."
He refused to rule out changing teams for 2011 when asked if Lorenzo's new deal had made him question his future with Yamaha.
"I don't know, we'll see," Rossi replied. "For next year I already have a signed contract, so we carry on as is, and then I'll decide what to do."
Although Lorenzo was immediately a frontrunner when he graduated from the 250cc series to the second factory Yamaha ride last season, a string of early crashes prevented him from being a 2008 title contender.
But with Honda's Dani Pedrosa making a slow start to the season and Ducati's Casey Stoner falling out of contention due to illness, the 2009 championship battle has developed into a Yamaha inter-team contest, with Rossi and Lorenzo currently 25 points apart going into the final five rounds.