I like both these guys.
Pats usually end up with an undrafted player on the final roster. Basically the law of averages says if each Day Two player has a 50% chance and each undrafted player has only a 10% chance, but you take a dozen of them, someone is going to make it from the udfa roster.
These two guys, I think, are near the top of the list of guys that could make it, based on the current roster.
The Pats are relatively weak at TE and P. So Drago has a decent chance. They also sometimes keep a kicker on the practice squad - they had the punter that beat up his dad a couple seasons ago.
DeVree sounds like a decent third TE - could compete with Spach, and certainly Pollard. And with Watson and Thomas, there could always be an injury spot.
Guyton and Redd also have a shot. Guyton brings a record as a very good special teams player, and could unseat Alexander based on his ST skills and defensive upside.