Matthews got torched by Carmelo Anthony and Kobe Bryant in the playoffs.
So what? Everyone gets torched by these guys. He is a rookie that made them work hard.
In all of Batum's games against Brynat Kobe scored 23, 26, 26, 32 and 20
In all of Batum's games against Anthony Carmelo scored 38, 12, 30, 25
Does this make Batum a bad defender? No it does not.
Let me remind you that when Roy was a rookie and he faced Kobe, Kobe scored 25 and 65 (yikes) against him.
Kobe Bryant is a fantastic player, as is Anthony, these guys are among the best scorers in the NBA night in, night out. They are going to score on people. All you want your defenders to do - is make it hard for them, and if you are lucky enough and have a good "mistake cleaner" big behind you - you make them take contested shots, or if they work hard to get by you - make it easier for the guys behind to clean up.
Utah had no shot-blockers, no real defensive interior presence. The Blazers currently have 3 of these guys on the roster. But, the Blazers, had bad perimeter defense that put the bigs in foul trouble last year. With Batum and Mathews on the perimeter and Oden, Camby, Joel inside, the Blazers will make life much much harder for opposing players.
If you look at head2head matches - you will see that Kobe scored in the 30s many times on Ron Artest, he had multiple games scoring 40+ points against Bruce Bowen. These guys are going to score, especially with the no-hands defensive rules of the NBA. You can never stop them, you can make them work hard, however, and it seems that Mathews is good at that.