Amid growing evidence that Sumner Redstone is planning sweeping changes at Viacom, speculation in the industry has turned to who might be recruited as the successor to CEO Philippe Dauman.

Much of the focus, sources have told Variety, is centering on Tom Freston, the former MTV Networks boss and Viacom CEO who was ousted by Redstone in 2006 and replaced by Dauman. Judy McGrath, Freston’s former top lieutenant at MTV Networks, has also been mentioned as a possibility.

It’s understood that there has been some communication in recent weeks between Freston and Shari Redstone, Redstone’s daughter, vice chairman of Viacom and CBS Corp., who has become an influential figure in her father’s affairs in the past few months. However, it’s not known if there have been any discussions of Freston returning to the company where he spent 26 years building up MTV, Nickelodeon and other cable assets. Some industry sources speculated that Freston might also be enlisted in a high-level advisory capacity if not for the full-time job as CEO.

Freston could not immediately be reached for comment on Friday.

The prospect of Freston returning to the company would likely play well with Viacom employees and with investors. Dauman’s regime has been criticized for a lack of attention to creative development and innovation at Viacom’s core assets including Paramount Pictures, MTV and Nickelodeon. Whether the successor is Freston or someone else, it’s likely that he or she will come from a strong creative background.

Viacom’s core brands have been in a slump in recent years and the stock is down more than 30% during the past year. Shares have inched up in the past two weeks since the drama surrounding Viacom began to point more specifically to the removal of Dauman as chairman-CEO.

Rumors of CEO successor candidates heated up in industry circles on Friday after reports surfaced that the nine Viacom board members not named Redstone were bracing for being ousted by Sumner Redstone. Viacom shares were up 4% at the close of trading Friday to $44.24.

Sumner Redstone’s National Amusements controls 80% of the voting rights in Viacom and also has broad discretion, per Viacom’s corporate bylaws, to replace board members at will. Should that happen, the nine directors are expected to file a legal challenge to the move in Delaware, where Viacom is incorporated.

Dauman is already suing Sumner Redstone over his ouster last week from the board of National Amusements and the trust that will oversee Redstone’s holdings after his death. Dauman has accused Shari Redstone of manipulating her ailing father, who turned 93 on Friday, to further her ambition of taking control of Viacom.

Freston has been active as a media investor and in philanthropy during the past decade since his nine-month tenure as Viacom CEO ended. Sources cautioned that it’s not at all clear whether Freston would want the job of running Viacom again were it to be offered.

In an appearance on Bloomberg News in March, Freston said the diminished state of MTV and its cable siblings “breaks my heart.”

(Pictured: Tom Freston)