The purpose of the study was to examine the effects of verbal interaction between students on skill development and soccer game performance within a socio-constructivist perspective and a cooperative learning model in team-sport teaching. In addition, the usefulness of open verbalization was manifested as follows: (1) a social tool for both actors (teachers and students) to collect and manage reports on their thought processes; (2) a tool to stimulate reflection and critical reflection on performance to induce transformation during game action projects. Participants were 18 boys and 12 girls aged (15 ± 0.4 years) from a Tunisian school (ninth grade). They were placed in either the experimental group (with verbal interaction) or the comparison group (without verbal interaction) and then were tested before and after a 12-lesson soccer unit (approximately two hours/week). Skill competence was assessed using three tests: a 15 m ball dribbling test, the Loughborough Soccer Passing Test (LSPT) and a shooting accuracy test. Game performance was measured using the Game Performance Assessment Instrument (GPAI) in which the outcome variables assessed included (a) decision-making (DM), (b) skill execution (SE), (c) support (S), (d) game performance (GP), and (e) game involvement (GI). While both groups showed significant improvements in their short-passing ability, no such improvements were found in dribbling and shooting. In contrast, only the verbal interaction group produced significant improvements in overall game performance. In conclusion, if the objectives of the physical education curriculum are to promote team-sport teaching methods and quality game play, and create a reflexive learner, verbal interaction may be an effective tool for developing tactical understanding through cooperative learning.