12/27/2008 - Under Armour Recruiting Classic 2008 Sebastian is a two way player in the outfield and on the mound with a solid average body that does show projection as it continues to physically mature. Foot speed is above average as indicated by his 7.19 60 time. He utilizes his quick feet in taking proper routes and angles in tracking down balls in the outfield, displaying plus range. He reads balls well off the bat, taking proper first steps and getting great jumps. Arm strength is average and needs to get on a strict long toss program to aid in developing more arm strength and carry on throws. Also, needs to work on lengthening arm action and utilizing feet more efficiently through the throwing process. At the plate, Rivera has solid average ability with average power. He has a solid understanding of situational hitting and makes contact. He does have some mechanical flaws that are hindering him reaching his full potential at the plate. Hitting grades and power numbers will increase with instruction and adjustments at the plate. On the mound, Rivera has an athletic delivery with solid rhythm. Hand separation is late causing his arm action to rush. He shows good command of the strike zone, attacking hitters. Fastball and breaking ball are average pitches at present time. Sebastian does project best in the outfield where he has abilities with a lot of room to improve. He is very coachable and willing to make adjustments.