Bad news for the Vampire Diaries fans as Steven McQueen may leave TVD to join Arrow as Nightwing, the former sidekick of Batman.

Possible Arrow season 3 spoilers ahead, you've been warned.

It seems that Nightwing could appear on Arrow season 3 and that his involvement with show could be announced at the San Diego Comic Con 2014.

Stephen Amell has revealed that in his Facebook page that he is going to announce a lot of things at the San Diego Comic Con 2014. It could be assumed that what he is going to announce at SDCC 2014 are some huge Arrow season 3 spoilers.

During a fan Q&A on Facebook, comics and webseries writer/actor Kevin Conn asked Stephen Amell what other DC characters he'd like to see on Arrow in the future. Stephen Amell answered with:

"Nightwing would be pretty badass."

Was this a hint at things to come?

Actor Steven McQueen began tweeting about "Nightwing" training and he kept tagging the Arrow writers with his tweets on Twitter. Check out his tweets below:

It should be noted that the producers of Arrow has stated that Nightwing won't appear on Arrow, it could be that they were referring to the fact that Nightwing won't appear on the Arrow season 2 (the rumors of a Nightwing appearance sprang up during the season 2 of Arrow) but on Season 3?

Stay tuned for Stephen Amell's announcement on SDCC 2014 but you can be sure that he would drop huge Arrow season 3 spoilers on that day.

On other Arrow season 3 news, Actress Devon Aoki has been cast as Katana and Mummy star Oded Fehr has been cast as Ra's Al Ghul.

Do you think Nightwing would appear on Arrow? Sound off in the comments below!