The newest Mav is a 6'5" guard who doesn't really do anything but shoot---but does it very well. Now 27, in his fifth year in the league, Morrow goes to his third new team bringing with him a .425 three-point percentage. That number is buoyed by startling early career success, and has fallen off in recent years, but he's still managing 40% in limited minutes so far this season.
Morrow has scored solidly, and had a solid PER whenever given a chance. His career 13.4 won't break the bank-it ranks just tenth on the Mavericks-but it is a sold improvement on Dahntay Jones, who was hanging a 7 in identical minutes this season and actually his points per play allowed, according to mysynergysports.com isn't horrible. He allowed .85 points per play last season, and .67 in isolation. He's not very good at it, though.
It's hard to know whose minutes Morrow will take, as he is not a PG, would probably get tooled by SFs, and SG is basically the only position the Mavs have down, with an incredibly potent OJ Mayo, Vince Carter rotation. Like all Mavs forever for the rest of our lives, Morrow's contract is expiring, so it's not overly likely you'll see much of him at all.
If he finds playing time, he could be a useful player on offense. Not more than that, but that's what you get when you trade Dahntay Jones. He's shooting a ridiculous 46% from the corner three and a surprising 46% from long two, a shot the Mavs love to take.
Welcome to the Mavs, A-Mo.