Miggy was barely 20 years old when he came into the league....dude filled out in his 20s. He was practically a kid when made his MLB debut.
I'm sure it's possible he is on some performance enhancing drugs, but he's never been remotely linked to them.
His numbers have been very consistent, with no tell tale monster spikes in production.
I'll never say never when it comes to that stuff....but I also don't believe in labeling that tag on someone without a shard of evidence....and him filling out in his 20s doesn't count.
Most dudes on roids get a lot of injuries and Miggy has played in 150+ games every year of his career, outside of the year he was called up as a rookie.