The purpose of this investigation was to investigate whether age, anthropometric characteristics, and athleticism of NCAA D3 collegiate baseball players were related to their playing status (starter versus backup). In the two weeks prior to the start of their championship season, 144 participants from three universities in the Great Lakes region of the Midwestern United States completed an assessment protocol consisting of standing and seated height, wingspan, weight, body composition, grip strength, countermovement vertical jumps on force plates, and 20yd sprints. Upon conclusion of their season, their year end statistics were evaluated to determine whether they met the criteria as a starter or a backup. Independent samples t-tests were then performed to determine if statistically significant differences in performance were observed on the assessment protocols by starters and backups. Overall, starters were significantly older than backups, and performed significantly better on all of the metrics related to performance on countermovement vertical jump. When investigating playing status by position (pitcher or hitter) different relationships existed. Starting pitchers were significantly older and produced significantly higher peak concentric power than their backups. Starting hitters were also significantly older than their backups, in addition to being better than the backups on assessments of grip strength, and several metrics derived from the countermovement jumps (flight time to contraction time ratio, relative peak concentric power, and jump height). [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]