Within two sections of science methods for elementary and middle-school teachers, an embedded, multi-case study design was employed to explore whether teaching rehearsals would better prepare preservice teachers (PSTs) to implement explanation-driven science instruction. A teaching rehearsal allows PSTs to practice teaching a segment of their lesson and receive in the moment feedback and an opportunity to redo instruction before implementing a lesson with children. One section (or case) engaged in a teaching rehearsal before implementing their first science lesson in their field experience classroom. They practiced how to support children with organizing, analyzing, and interpreting data, introduce the Claim, Evidence, and Reasoning (CER) framework, and guide students through the process of constructing a scientific explanation. The other section (or case) did not engage in a teaching rehearsal. All PSTs in the teaching rehearsal group were able to successfully engage students in a sense-making discussion to identify patterns in the data, introduce the CER framework, and support students in collaboratively forming a claim as well as multiple pieces of evidence. These findings are contrary to the non-teaching rehearsal group where an in-depth discussion of the data occurred when providing evidence to support a claim. As a result, some inaccurate or incomplete claims were constructed and supported by vague evidence. Both groups struggled to support students through the process of constructing a reasoning statement that fully justified the claim and evidence. These results demonstrate that teaching rehearsals help prepare PSTs to implement several aspects of an explanation-driven science lesson.