I'm a lurker here as well as undergraduate assistant coach for the new University of Oregon baseball team. I got the chance this spring to see a few players the Mariners could potentially draft.
(SS) Grant Green, USC: He's 6-3 and lanky but needs to add about 20 pounds of muscle. Has good speed and great instincts. He's a great hitter; tons of power when he pulls and does a good job letting the ball travel and serving it the other way. I was disappointed with him defensively. His arm was average and his glove was just ok. Although I haven't seen him live, I believe Ackley would be the more appropriate pick.
(OF) Brett Jackson, CAL: Jackson has big-league size, big-league speed, and a big-league arm. While he struggled against us in our series down in Cal, I could still see why so many people like him. His swing is so smooth and he has so much power. He hit a triple down the right field line and it was the most impressive thing I saw from a player all year. If you haven't seen him on YouTube running a triple, I strongly suggest you watch it. The kid can really really run, and it shows on the defensive side as well. He plays great great defense. If he's available at #27, I would be ecstatic to get him.
(RHP) Mike Leake, ASU: While he may not look like a first-round pick (5-11, 180), Leake has certainly performed like one. Fastball is 89-93 with huge armside run, two-plane sider about 82-84, and a very special change-up. I won't look up the stats, but I know that Leake has been one of the most successful D1 pitchers in the nation over the last 3 years while pitching in a hitters ballpark. He is gritty and is a thinker. Sets up all his pitches well and has the ability to pitch all hitters backwards. Great pickoff move and is a warrior. However, #33 might be a bit of a long-shot for Leake considering his physical attributes.
(OF) Jason Kipnis, ASU: If the M's were so somehow pass on Ackley, their next target in later rounds should be Kipnis. Bats Left Throws Right. Pesky hitter who hit .363 this year with an OPS over 1.000. A very tough out, drives the ball all over the field, and great speed (24 SBs). Plus arm in the outfield with above average defense. Would be a solid, third or fourth round selection.
(SS) Ben Orloff, UC Irvine: The smartest college baseball player I have ever seen. I don't know when he is projected to be drafted but I would be very excited to get a guy like this. If you get a chance to watch Irvine play in a Regional or in Omaha, please do. Has every attribute of a leader you could ever ask for. Doesn't have the physical make-up of a big-leaguer but he will make it there anyways. David Eckstein type player. Tremendous bat control, decent speed, great glove, smooth and gritty. Watch Ben Orloff if you get a chance.
(LHP) Tyler Matzek, Mission Viejo, CA: Some rank him the top high school pitcher in the country. Committed to the University of Oregon and would likely come to us if he falls out of the top 15. I've heard talks of the Mariners taking him with the number 2 pick but I highly highly doubt that will happen. 6'5'', lanky lefty, fastball can hit 95 and has a huge slider. Change-up and control will need a little more work. I imagine he will be picked in the top-10 but if not, he will attend Oregon and be the number 1 overall in 3 years. TREMENDOUS upside.