Lukather has been in the studio with long-time Steely Dan collaborator Keith Carlock, working on a forthcoming Toto album, but the drummer will not be with him on the Toto concert dates to follow. Lukather says that Carlock, before joining Toto, had committed to one more tour with Steely Dan — to take place this summer. Steely Dan has not yet mentioned plans for another round of shows.

Toto will be appearing instead with Shannon Forrest, who has previously worked with Toto’s 2014 touring partner Michael McDonald. Carlock, who replaced long-time collaborator Simon Phillips, will then return as Toto’s drummer in 2015, Lukather says. Phillips joined Toto in 1992.

“Keith is the only drummer on our record,” Lukather says, “and he will be in the band — but there is one last Steely Dan tour he was committed to this August before we asked him to join.”

Meanwhile, Nathan East — who has just released his first-ever solo album — is stepping aside for original Toto bassist David Hungate, who left the group subsequent to their blockbuster 1982 release IV. East had been a touring member of Toto since 2010.

“As it seems the news is out,” Lukather says, “yes, we are very happy and honored to have Hungate do the USA tour with us. Nathan is busy with Foreplay and his solo career now and is leaving. He was great but, like Simon, he needed to go with his own career — and we are all still great friends.”