The Italian marque's Paul Hembery said in Milan that, so long as the contract to supply tyres to F1 teams is extended beyond 2013, Jaime Alguersuari and Lucas di Grassi will almost certainly keep their jobs this year.
Spaniard Alguersuari, however, wasn't confirming the news.
"Sorry, I haven't confirmed my future yet," he wrote on Twitter. "I'm still working on it so I can give you news soon. Sorry for the delay."
Hembery thinks staying would be a good move for Alguersuari.
"Jaime learned more in one day of testing with Pirelli than he did in his entire career with Toro Rosso," he is quoted by Spain's AS newspaper.
As Pirelli launched its new, softer and faster tyres for 2013, Briton Hembery insisted: "There is no reason for us to change our drivers.
"We have had a great time with Alguersuari and di Grassi," he is quoted by Brazil's Totalrace. "We need to renew our contract with formula one first, and then we'll go ahead."
Hembery said the 2013 generation Pirelli will require drivers to make more pitstops and promote more overtaking, while the identification colour for the hard tyre has been changed from grey to orange.
But when asked about this year's tyres, Fernando Alonso said on Twitter on Wednesday: "They are practically the same as in 2012."
Hembery also said this year's GP2 champion will win a formula one test with Pirelli, and that the marque will keep the 2010 Renault as its F1 test car.
"There is not the need to get a newer model, since the cars in 2014 will be completely different to the current ones," he said.