My hero is an average European city boy of the 21th century. Eighteen years old, doing a bit of sport, eating well, with a job that doesn't require much physical efforts. He would appears just as normal as you, or I, do. For the sake of the story, he will be white of color with blue eyes.
By a series of spectacular events, he winds up through time up to the years ~200 A.D. where he meets with a local village between Macedonia and Gaul in the Ancient Rome. It is a really small entity, composed mostly of farmers and perhaps few blacksmiths or carpenters, which is an average in the countryside... and naturally, the people of this village will react to the newcomer.
The question (s)
How do this guy appears to the local residents, physically speaking? Is he seen as a well-built male, a weak boy or a totally normal resident? Does he appears young and ugly, or old and wise? Will he be able to do the work of a farmer, or will he collapse on the first day?
...and more importantly
Does he have a chance to join the auxiliary troops of the roman legion?
PS: This is not about his clothes. To avoid confusion, let's imagine he managed to find local clothes that won't make him look weird to the people.