Research has revealed that student teachers benefit from teaching practicum programs. The programs present the student teachers with myriad opportunities to negotiate and deconstruct their personal and practical knowledge with the help of teacher mentors and supervising faculty members. This study reports on a case study that examines the deconstruction of English student teachers' changes in expert and practical knowledge during their teaching practicum. Seven student teachers (two males and five females) were involved in this study. The data were gathered from reflective journaling and interviews documenting their prior learning experiences during teaching practicum. A self-reflection framework by Dewey was employed to analyze the data. The findings have indicated that the student teachers encountered both enjoyment and dissatisfaction. Enjoyment included materials beyond the textbook, opportunities to express ideas and classroom activities, moral messages, and understanding of teaching and learning. Dissatisfaction occurrences are linked with textbooks and workload. By deconstructing expert and practical knowledge using reflective practice, there is an urgent need for stakeholders including mentor teachers and supervising faculty members to reframe practicum systems to offer more opportunities to maximize experiential interaction, in addition to their formal authorized clinical role. By doing so, a new perspective might be running in line with the development of improving the quality of teaching as a direct impact of practical pedagogical knowledge.