The fourth installment in the "High School Musical" franchise is currently in the middle of production, and many fans have been hoping to see the return of Vanesa Hudgens and Zac Efron, who portrayed Gabriella Montez and Troy Bolton, in the 2006 installment.

Latest reports claimed that Hudgens already agreed to work with Efron for "High School Musical 4: Wild and Knights." It is believed that the two will play as vocal mentors to the new breeds of wildcats.

While no confirmation has been made yet, the American actress-singer ambiguously hinted her possible return by posting a throwback photo of her with the series' original cast on Twitter with a caption that reads, "A little #TBT for all the HSM fans."

Talks about Hudgens and Efron's possible return heightened when the latter posted a photo of "High School Musical" on his Instagram account.

While many are glad about the news, some fans are still doubtful about the ex couple's special appearance in the upcoming "High School Musical 4: Wild and Knights." According to a report by The Bitbag, Hudgens' current boyfriend, Austin Butler, reportedly disapproved any sort of contact with Efron.

It can be recalled that Efron and Hudgens' on-screen romance went to become a real-life relationship two years after they worked on the first installment of the "High School Musical" series. The two shortly ended their relationship in December 2010.

Meanwhile, actress Ashley Tisdale, who played the high school diva Sharpay Evans, dismissed previous reports claiming that she will reprise her role in "High School Musical 4: Wild and Knights."

"Sharpay was such an awesome character, but at the end of the day it was a character, it wasn't me," Tisdale told New You magazine, as cited by Seventeen. "Looking back, it was such a perfect thing for its time and was so pure that I just don't know how you go from there. 'High School Musical' didn't make us, we made 'High School Musical' because of our friendship, how close we were, and the magic there at the time."

"High School Musical 4" is expected to air in 2017. Stay tuned for more "High School Musical 4" news and updates here.