‘Arrow’ Season 5 Spoilers: Dolph Lundgren Joins Flashbacks; John Diggle Absence, Roy Harper Return Rumored

A host of major changes are in store for the Emerald Archer in the upcoming next season of The CW's "Arrow," with action star Dolph Lundgren set to join the cast along with the possible return and departure for some members of the series' previous regulars.

One of the first major changes for the season 5 of "Arrow" is how it will continue its storyline in peeks at the checkered and mysterious past Oliver Queen (Stephen Amell). Though longtime fans and viewers of the show already know it, prospective viewers might not know of how Oliver spent five years in a deserted island, or hell as the season 4 intro monologues call it, before he came home and crafted his vigilante persona.

The first couple seasons took place firmly on the island, Lian Yu, with season 3 moving the vents to Hong Kong. Season 4 eventually moved back to the island, though with a brand new conflict that connected with the present day storyline.

For season 5, the flashbacks are reportedly set to move Oliver all the way to Russia and touch back on his long mysterious connection with the organized crime syndicate; the Bratva. Though it is not yet clear as to how his connection to the organization is, the major antagonistic force in the flashback storyline will be "The Expendables" star Dolph Lundgren.

Speaking with TV Line, "Arrow" showrunner Wendy Mericle described Lundgren's character as "a government strongman. He is scary and formidable - and he had a role in some stuff with Taiana's family last season. He's a bit of a badass."

Taiana Venediktov is the major supporting character of the previous season's flashbacks, played by Alysia Rotaru. She assisted Oliver in standing against the heinous plans of Baron Reiter, despite Oliver's defensive killing of her brother. Unfortunately, events later conspired against them when circumstances arose that required Oliver to kill her.

Season 5 will reportedly have Oliver trying to fulfill his promise to Taiana, that is to inform her family of what happened to her and her brother, only to apparently be met with Dolph Lundgren's character.

For the present day storyline, there are also beliefs that the cast will undergo some major changes according to Moviepilot. One of those changes is the possible departure of John Diggle (David Ramsey), as well as the equally possible return of Roy Harper (Colton Haynes).

Season 4 ended with John proclaiming his re-enlistment with the Army, owing to the recent tribulations he faced in the season's conflict. One of those tribulations is his own killing of his brother Andy (Eugene Byrd). The publication believes that with that turnout of events, the "Arrow" writers might be planning on giving the character a break for this season.

Contrasting John's possible departure is the return of Roy Harper, also known as the sidekick of the Arrow before he became the Green Arrow. Haynes left the show in its third season, owing to his emotional problems back then, which caused his character to be written out as also leaving the team. Haynes returned for a short time during the past season, with his apparent growing recovery in recent times believed to be a sign of his possible return to the show.

Season 5 of "Arrow" will return on Oct. 5 on The CW.