The "Dancing With The Stars" 2017 pro cast was formally unveiled during the Aug. 24 episode of "Good Morning America." Although the announcement ushered in the happy return of fan favorite Mark Ballas and confirmed the participation of several popular dancers including reigning pro champ Emma Slater, two-time Mirrorball Trophy winner Valentin Chmerkovskiy, and newlyweds Peta Murgatroyd and Maksim Chmerkovskiy, the unexpected absence of Sasha Farber drew disappointed reactions from fans -- and Slater, who is Farber's fiancee.

Emma Slater tweets about Sasha Farber

Farber, who proposed to longtime girlfriend Slater during the Oct. 4, 2016 live broadcast of "Dancing with the Stars," last competed during the show's spring 2017 season. He and celebrity partner Simone Biles placed fourth behind winners Slater and NFL star Rashad Jennings.

Slater reacted to Farber's omission from the "Dancing with the Stars" 2017 pro lineup shortly after the cast was revealed by tweeting:

The 28-year old dancer did not comment on the reasons behind Farber's absence from the cast list and did not respond to comments by disappointed fans who questioned why he was not in the mix.

Sasha Farber reacts

Following the "DWTS" pro cast announcement, Farber also hit Twitter to express his thoughts. Initially the 33-year old dancer simply tweeted ":(". Twenty minutes later, he thanked fans for their heartfelt messages of support:

He added two additional congratulatory messages, including one to Slater, and another to Mark Ballas, who last competed during season 22 with mixed martial artist Paige VanZant.

Of Ballas, he wrote "missed his creativity gonna enjoy watching his work!"

Full 'Dancing with the Stars' season 25 pro cast

The full "DWTS" 2017 pro cast lineup is as follows, per "Good Morning America":

  • Emma Slater
  • Lindsay Arnold
  • Witney Carson
  • Sharna Burgess
  • Peta Murgatroyd
  • Mark Ballas
  • Valentin Chmerkovskiy
  • Maksim Chmerkovskiy
  • Artem Chigvintsev
  • Keo Motsepe

Although the announcement also teased that a 13th pro dancer would be unveiled during the Sept.

6 celebrity cast reveal, just hours later, ET broke the news that the mystery professional is actually two-time "Dancing with the Stars" winner Cheryl Burke. Burke most recently competed on the hit reality TV show during season 23 alongside Olympic champion Ryan Lochte.

"Dancing with the Stars" 2017 begins Sept. 18 on ABC. Watch "Good Morning America" on Sept. 6 to catch the full cast reveal.