Notable Guardian of the Galaxy Groot was present in the Season 2 premiere of Marvel’s animated series What If…? but Vin Diesel’s voice was nowhere to be heard.

Voice actor Fred Tatisciore took over for Vin Diesel in What If…?’s Season 2 premiere episode, according to the credits. This marks the very first time that the character has not been voiced by Diesel.

It’s significant to note that despite not returning for What If…?, Vin Diesel did lend his voice to the computer-animated I Am Groot series of shorts on Disney+.

Marvel Studios

Several other established MCU stars did come back to record voice work for the premiere though including Karen Gillan as Nebula, Michael Rooker as Yondu, and Jude Law as Yon-Rogg. Korg, Garthan Saal, and Howard the Duck were also present, voiced by their original live-action actors as well.

In What If…?, the MCU takes the opportunity to dive into the Multiverse and showcase what goes on in universes that fall outside of the Earth-616 timeline.

Of course, this being an animated show, not every actor from the live-action Marvel Cinematic Universe has opted to reprise their role. This has resulted in several characters having their performers replaced with soundalikes.

I Am Groot? (Translation: Who Else Didn’t Return for What If…?)

Marvel Studios

Groot had a very minimal role in the episode itself, so it isn’t like Diesel’s absence is a glaring omission. But there are several other stars from the MCU who declined to reprise their characters for What If…? Season 2, or simply were not able to participate.

While a complete list of actors who didn’t come back has yet to be seen, just going by the voice replacements from Season 1, it’s safe to say that fan-favorite Robert Downey Jr. isn’t voicing Tony Stark. The same can be said for Scarlett Johansson as Black Widow.

Instead, those roles went to Mick Wingert and Lake Bell, respectively.

Stark and Romanoff are big-name, high-profile heroes but it does make sense that their original actors didn’t voice them in animation. Johannson and Downey Jr. are huge stars with very busy schedules. Not to mention that What If…? simply may not have had the budget to hire them.

But there are a great number of actors that the series did get back, even going as far as to cast the actor who played T’Chaka in Black Panther’s flashback scenes as his animated counterpart.

What If…? Season 2 has adopted a fairly unique release schedule.

Starting on Friday, December 22, Disney+ will put out one new episode a day for nine consecutive days, ending on Saturday, December 30. The first one can now be streamed.