Jacob Fatu was written off television after being attacked by a mystery figure on WWE SmackDown. In real life, the Samoan Werewolf is suffering from an injury that led to this decision.However, the Stamford-based promotion left the mystery-attack angle intact, and the attacker will likely be revealed when Jacob returns. In this article, we will discuss three indications suggesting that 12-year WWE veteran Sami Zayn could be behind this sinister act.#3. Jacob Fatu had issues with himJacob Fatu and Sami Zayn already had a heated history on SmackDown. The Samoan star never liked Sami on television, and they were mostly rivals. The only time Jacob was seen with Zayn was when Jimmy Uso was involved, too.Even during a backstage segment, Jacob expressed his unhappiness with Sami when the former OG Bloodline member tried to befriend him. This history is enough to say that Sami Zayn has a realistic chance of being the mystery attacker.#2. Is Sami Zayn hiding a darker side?Roman Reigns SZN 💥 @reigns_eraLINKCrying. Now Sami’s staring at Cody’s title 😭 #SmackDownRecently on SmackDown, Sami Zayn was seen staring at the Undisputed WWE Championship when he was engaged in a backstage segment with Cody Rhodes. This sparked speculation that Zayn will turn heel in the near future and finally get a WWE World title shot.However, this behavior suggests that the ex-United States Champion may be hiding his darker side and is badly seeking a world title shot. This could be why, when Jacob Fatu tried to get a title shot against Cody Rhodes, Sami potentially attacked him, taking him out. He may not have wanted someone like Jacob to earn a title shot before him.#1. Jacob Fatu didn't have his back when MFT cost Sami Zayn his US title on WWE SmackDownOne of the main reasons Sami Zayn lost the United States Championship on SmackDown was Solo Sikoa. The MFT leader distracted him, allowing Ilja Dragunov to secure the victory and emerge as the new Champion.Despite Jacob having issues with Solo Sikoa and Sami helping him many times, the Samoan Werewolf didn't have his back when Solo cost Zayn on SmackDown. This could be why the 41-year-old star might have decided to take Jacob out backstage and eventually attacked him a few weeks back.Overall, the unveiling of the mystery attacker on WWE SmackDown will be interesting to witness, especially if Sami Zayn is revealed as the person behind this.