This little detail is touched upon several times in the film, most likely so that Gunn can explore it later on. A scene with Rocket in the Kyln shows that he's been cybernetically enhanced, and he's not the only one. Gamora, Drax, and the villainess Nebula all have cybernetic implants of some kind, so exploring where those came from and why they were added could easily flesh out their backstories a bit more and give Gunn a compelling story to tell. Rocket's backstory in particular would be interesting to explore, especially since he appears to be an audience favorite. Of all the Guardians, he's perhaps the most scarred, after being created in a lab and experimented on again and again. His tearful monologue about the subject definitely won't be the last we hear of the traumatic experience.