The Genoa-based club posted a tweet which featured a silhouetted player against the backdrop of the word Ronaldo in large letters -- and the word Vieira in tiny ones underneath -- and the message: BREAKING #Sampdoria sign #Ronaldo.
Juve's announcement last month featured the word Cristiano behind a silhouette of the Portugal forward in his familiar celebration pose, with feet wide apart and outstretched arms.
Vieira, 20, was signed from English second tier club Leeds United where he turned professional two years ago.
News that makes sense
Your trusted source for staying up-to-date with the world around you. Get free daily news updates and analysis, straight to your inbox.
"Two different Ronaldos -- he's a big, big player and I want to get to that stage. Obviously, I'm still young and I've got to try and learn as much as I can," Vieira told Sampdoria's Youtube channel.
Born in Guinea Bissau, Vieira lived in Portugal for 10 years before moving to England in 2011.
In a message on his own Twitter account, he appeared reluctant to leave Leeds.
"Sometimes in life things don’t go as you want them. Sometimes things are out of your control," he wrote. "But then you have to take these opportunities and give it your everything the same way I have always done."
(Writing by Brian Homewood, editing by Pritha Sarkar)
