Manchester City have been linked with midfielder Paulinho, while striker Guerrero is thought to be on the radar of Chelsea after scoring against them in the FIFA Club World Cup final.
Goalkeeper Cassio and forward Juan Manuel Martinez have also attracted interest from elsewhere after impressing for the Brazilian club.
But Gobbi is adamant Corinthians are only looking to strengthen in January and will not be letting any of their stars leave.
He told Terra: "The principle is to strengthen [the squad], not to let any player leave.
"Our cycle is from July to July, so until the end of the Copa Libertadores, our squad will remain the same. Nobody will leave."