Ask and ye shall receive:
From Razzball.com, quoting unnamed scout and scouting report(s):
From an mlb.com article written when Alonso was drafted:His defense was acceptable at best; his base-running was adequate; his hitting eye is just short of amazing; and his swing is jaw-dropping and magnificent.
From Hardball Times:Scouting reports about his defense aren't overly enthusiastic, however.
His defense can't really be considered more than average, and although he makes the plays he can get to, his range is limited.