So far, a few Guardians actors have been confirmed in DC roles, such as Maria Bakalova (Cosmo in Guardians of the Galaxy Vol. 3) playing Princess Ilana Rostovic in Creature Commandos and Nathan Fillion (various roles throughout the Guardians franchise) playing Guy Gardner in Superman: Legacy.
In addition, both Chris Pratt and Pom Klementieff have both teased involvement in the rebooted DC universe in some capacity, with Pratt saying he would do it if asked, and Klementieff speaking to "conversations" she had about it. Since these teases, much fan speculation has occurred about what their involvement could look like.
Chris Pratt's Possible DCU Involvement
In a response to a fan post on Threads, DC Studios co-CEO James Gunn indicated that both Chris Pratt and Pom Klementieff could have roles in his rebooted DCU.
"I would like some from the cast of 'GotG' to guest star in the next season of 'PeaceMaker,' as themselves, like Chris Pratt being himself or Pom herself.."
Gunn responded, explaining that "there are reasons" he would not want Pratt to play himself in the rebooted DC universe:
"There are reasons I wouldn’t want either of those actors to play themselves in the DCU!"
This is obviously not a casting announcement, or anything close to such. However, it is an indication that Gunn may have plans to cast Chris Pratt in a notable DCU role, of which would be impeded on by him appearing in-universe as 'Chris Pratt.' If nothing else, it implies the director is at least considering the possibility.
Could Chris Pratt Have a Large Role in the DCU?
Interestingly, Gunn is not against one actor playing multiple characters within a single universe. Sean Gunn often plays, voices, or offers motion capture work for several characters within a movie, and Nathan Fillion played a different character in each of the Guardians of the Galaxy movies.
However, in both those situations, the roles played either hide the face of the actor in question or appear only briefly in more of a cameo setting. As such, it would not be too far off to figure that Gunn not wanting Pratt or Klementieff to cameo as themselves implies him wanting to save them for something bigger.
That could mean a significant role in a single project, or a smaller role in multiple projects. If either actor appeared as themselves before debuting in their actual role, it would break continuity in a capacity that is harder to overlook than it would if one actor had multiple cameos as different roles.
But for all fans know, these "reasons" could be completely unrelated. The response was vague, leaving open several possible interpretations.
The new DCU officially kicks off with Creature Commandos, coming in 2024.