This study examined the relationship between anthropometric and physiological performances among youth soccer players and the positional differences for these variables. Seventy U14 male soccer players (goalkeeper: 10, defender: 20, midfielder: 25, and forward: 15) participated in this study. Body mass was significantly (p < 0.05) correlated with ball shooting speed (r = 0.58) and 30 m sprint time (r = -0.54). Body height was significantly (p < 0.05) correlated with vertical jump height (r = 0.36), 10 m (r = -0.32) and 30 m (r = -0.64) sprint times, Yo-Yo intermittent endurance run (YYIER) distance (r = 0.26), and running time during maximal oxygen uptake (Vo2max) (r = 0.35). Body mass index (BMI) was significantly (p < 0.05) correlated with ball shooting speed (r = 0.31), 30 m sprint time (r = -0.24), Hoff test dribble distance (r = -0.29), YYIER distance (r = -0.25), submaximal running cost (r = -0.38), Vo2max (r = -0.42), and the corresponding running time (r = -0.24). Significant positional differences were observed in anthropometry (body mass [p < 0.01], height [p < 0.01], and BMI [p < 0.01]) but not in physiological performances. This study provides a scientific rationale behind the coaches' practice of selecting young soccer players according to their anthropometry for short-term benefits such as heavier players for higher ball shooting speed and 30-m sprint ability as an example. However, this does not justify such practice in the long-term process of player development.