Jack is a portfolio manager at XYZ Asset Management, managing an active equity portfolio for a client with a long-term investment horizon and a high risk tolerance. The client's investment policy statement allows for significant sector tilts and a relatively concentrated portfolio. Jack's top-down analysis suggests that the materials sector is poised for outperformance due to increasing demand for raw materials and a global economic recovery. However, the portfolio currently has a significant underweight position in the materials sector relative to the benchmark. Jack has identified several high-quality materials stocks with strong fundamentals and attractive valuations that he believes will generate alpha. What is the most appropriate approach for Jack in this scenario?