When will a MMA fighter step in the boxing ring?

[βetamax]

that's not a real boxing match against a real professional.
that guy he's fighting is probably a bouncer who gets hit in the face as a side job.

It was his first and only pro fight lol

[AntDawg]

Toney and Mayorga have shown they have the guts to get in the Octagon. When is a UFC guy going to do the same?

[Dirt]

anderson silva, vitor belfort, andrei arlovski to name a few have been in the boxing ring. I don't know what their records are though.

besides, boxing is only one area in MMA. MMA fighters are more well rounded (not that im saying mma is better than boxing. i like both)

[DE100]

Cant cut it in boxing or retired? Go to MMA
Cant cut it in the NFL or retired? Go to MMA.
Done Wresting? Go to the MMA.
Done with kickboxing? Go to the MMA

etc... Rare to see it the other way around, and if they try its on some local level type stuff, not Grand PPV events like these Former Athletes of other sports get in MMA.