Meanwhile, within an hour of McIlwain's declaration, news emerged that Kyler Murray, the top two-sport star from last year's Draft class, will transfer from Texas A&M. The fact that Murray would be forced to sit out a year in both baseball and football if he transferred to another Division I program has led to speculation that he might attend a junior college instead, which would make him Draft-eligible in 2016.
After focusing on football for much of his prep career at Council Rock North (Penn.) High, McIlwain saw his MLB Draft stock gain significant traction over the summer with strong performances at the Perfect Game National Showcase and Area Code Games. At the latter event, the 6-foot-1, 205-pound outfielder impressed scouts with his plus bat speed, producing multiple triple-digit exit velocities, as well as an improved feel for barreling the ball.
• 2016 Draft order
Even before his announcement, McIlwain, one of the top quarterback recruits in the nation, was expected to be difficult to sign due his strong commitment to South Carolina. As a senior, he threw for 1,727 yards and 17 touchdowns, using his plus speed to tack on another 1,528 yards and 30 touchdowns on the ground. Following the season, he was named Gatorade Player of the Year in Pennsylvania.
McIlwain just missed the cut when MLBPipeline.com released its Top 50 Draft Prospects list in early December.
Murray was the nation's top-rated dual-threat quarterback as a senior at Allen (Texas) High, where he guided the Eagles to a 42-0 record and three consecutive state championships as a starter.
He went on to appear in nine games for the Aggies this fall, throwing for 686 yards and five touchdowns. He also ran for an additional 335 yards and a touchdown.
On the diamond, Murray ranked as MLBPipeline.com's No. 34 Draft prospect before opting out of the Draft in early May to pursue both sports at Texas A&M.
While a shoulder injury limited his exposure in front of scouts, Murray still showed some of the loudest tools in his class, with well-above-average speed, a quick right-handed bat and surprising pop for his size. A shortstop in high school, he was expected to see time in Texas A&M's outfield next spring.
Murray was a candidate to come off the board on Day 1 of the 2015 Draft, and it's a safe bet droves of scouts will come out to see him this spring should he take the junior college route.
For McIlwain, simply tweeting his intent to attend South Carolina doesn't preclude him from being drafted or signing with a Major League team.
There have been several players who requested teams not select them, only to change their minds and sign after getting picked. Perhaps the most prominent example came in 2011, when Jesuit College Prep (Dallas) slugger Josh Bell wrote a letter to the Major League Scouting Bureau in May stating he did not want to turn pro and instead would attend the University of Texas, where his mother was a professor. However, the Pirates still drafted him in the second round and ultimately lured him away from his commitment with a $5 million bonus, the largest in Draft history for a non-first-rounder.
The 2016 MLB Draft will be held on June 9-11. Day 1 of the Draft will be broadcast live on MLB Network, while all three days will be broadcast on MLB.com.