This interests me also. Ignoring how unlikely it would be for a gladiator to be maimed in such a way to start with, if a gladiator was not mortally wounded but was obviously way past being able to fight again, would the skilled roman doctors even have bothered to treat him as they would the other gladiators who were still of use and very expensive?

If it was a flesh wound you might actually live there were "doctors" in Rome at that time who were exceptionally skilled at treated flesh wounds sustained by gladiators. The famous physician Galen was an example of this kind of Doctor. www.academia.edu/3614775/Galen_and_the_Gladiators_Episteme_5_1971_98-111_revised_with_an_Epilogue_2013