I'd put him in with any of the top LWW, its a shame he wont get a chance at Khan (should he beat Garcia) or JMM who will be looking for a couple of big name fights before retiring most likely.
Matthysee is a beast though, solid chin, powerful, puts on excellent pressure, can in-fight very well, picks his shots and has a decent defence.
Rios would be an awesome match and I think Matthysee would destroy him, Maidana would be an excellent all Argie bout with two bangers, again I would favour Matthysee.
Other than that there is a rematch there with Judah to be had and I think he would be more than happy to fight the likes of Provodnikov, Alvarado, Olusujen etc.
Guzman would be a good fight as well with the winner really making a statement to the division. Look forward to watching more of him no matter who he fights.