Sure, he has struggled a bit more at 5-on-5 so far this season than he did last season, but his start is surprisingly similar to last year's first 17 games. Prior to last night's game, Matthews had scored 7 goals, the same as he did last season through 17 games. He entered last night with 2 more points (17) than last season (15) when he set a career high with 106 points and scored 60 goals in 73 games.
Matthews will get going 5-on-5, but there's no reason to panic about his production. He is producing, he's just doing it in different ways right now. Also, since Keefe reunited Matthews with William Nylander, his 5-on-5 play has been much better.