Ducati MotoGP sporting director Paolo Ciabatti says Pramac rider Danilo Petrucci should be "smart" and look for a factory ride elsewhere for the 2019 season.
Petrucci revealed last month that the 2018 season would be his last with the satellite Pramac team, amid reports that the team is preparing to sign Moto2 rider Francesco Bagnaia for next season.
He also disclosed that Ducati has an option, expiring in June, to promote him to its factory team.
But the manufacturer's priority is to maintain its current works line-up of Jorge Lorenzo and Andrea Dovizioso, whose current contracts both expire at the end of the year.
Petrucci is adamant he wants to step up to a factory bike in 2019, and Ciabatti said the 27-year-old should focus his efforts outside of the Ducati stable - with Aprilia considered a likely option.
"The goal of Ducati is to keep our current official riders," Ciabatti told Autosport.
"We've made an investment with Andrea and Jorge and we have to try to renew with both of them.
"Danilo should be smart to go and find an [alternative] factory team.
"His programme with Pramac finishes this year and I think he's a rider suitable for an official structure.
"It's normal that he would want more money and in that sense everything is related to signing with a manufacturer, whether that's ours or another one."
Petrucci enjoyed his strongest MotoGP season to date in 2017, scoring four podiums and ending up eighth in the standings, second only to Tech3 Yamaha's Johann Zarco among the privateers.
Aprilia made an effort to lure Petrucci last season to replace Sam Lowes, but ended up signing Scott Redding to partner Aleix Espargaro for 2018.