Arrow Season 4 SPOILERS: Oliver Queen's Father, Fractured Relationship with Diggle

The CW's Arrow returns with the Season 4 premiere on Wednesday, October 7 at 8 p.m. Eastern, and we've got some new spoilers on Oliver Queen (Stephen Amell), including his father and his fractured relationship with Diggle.

Firstly, Entertainment Weekly caught up with showrunner Wendy Mericle and executive producer Marc Guggenheim. The latter talked about how Oliver will be different when we come back for Season 4.

“We played him as a guy who was returning home from war with PTSD for the first three years," Guggenheim said. "Now he’s put those demons to rest, or so he thinks, and there’s a lightness to him as a result of all the things he learned last year."

This makes sense considering what we have seen in the trailers and the fact that Oliver will start to lean toward the Green Arrow persona more in the fourth season. Mericle, meanwhile, noted that Oliver's quest in Season 4 is "less about erasing his father’s legacy and more about establishing his."

In a separate interview with TVLine, Mericle talked about how Oliver and Diggle (David Ramsey) are still on the outs when Season 4 begins after what Oliver did in the final episodes of Season 3. As a refresher, Ollie went deep undercover to infiltrate the League of Assassins and take out Ra's al Ghul, but this plan involved kidnapping Diggle's wife, Lyla. There was still plenty of bad blood between the two men as the season drew to a close, and that will be explored in the early part of Season 4.

"One of the things we’re really excited about in the first half of the season is, how does Oliver win [Diggle] back?" Mericle said. "When they meet again at the top of Season 4, it is frosty. It is not good. In the past, Oliver would have been very defensive and maybe written Dig off or really defended his position. What’s interesting now is that he’s in a different place. He’s happy with Felicity. He’s more willing to say, 'Maybe I made some mistakes.' Their reconciliation, how they get there, is going to be a bumpy ride. It’s not going to be fully resolved."

What do you think will happen in Season 4 of Arrow? Let us know in the comments section.