Question: Can collaboration techniques from another performance environment inspire Lean Construction theory? Purpose: The Norwegian football club Rosenborg BK (RBK) was a well-recognized force in European club football during its heyday in the 1990s. Led by the legendary coach Nils Arne Eggen, they regularly shocked Europe’s top teams with great results after implementing a successful philosophy based on collaboration. The importance of collaboration is well-emphasized in Lean Construction (LC) theory, but more discussion about creating a willingness and culture for collaboration seems to be lacking. Therefore, this conceptual paper suggests broadening the existing theory by presenting Nils Arne Eggen’s “Best Foot theory” principles through a new theoretical lens. The collaborative “Best Foot theory” is seen in an LC context and discussed with the “Five Big Ideas” from Lean Project Consulting, Inc. as the starting point. Research Method: A conceptual approach is used by analyzing already accessible data from another branch of knowledge and presenting it in a different context to offer another perspective to the current Lean Construction literature. Findings: A collaboration mindset that can inspire further development of the Lean Construction theory is proposed. Much of the current theory about collaboration in LC projects focus on collaborative contracts, systems, and approaches and fails to consider creating a collaborative culture among the performers. The “Five Big Ideas” are contemplating this, and the “Best Foot theory” adds more meat to the bones by giving successful practical examples for each idea. Limitations: This is a conceptual paper, and the practical applicability of the findings is not explored in a construction context. Implications: The “Best Foot theory” expands current LC theory by giving successful practical examples on how to create a culture where the practitioners in a performance group want to collaborate. Value for authors: The paper expands current theory on collaboration in LC. Keywords: Lean Construction, Collaboration, Culture, Trust Paper type: Full paper