In April 1966 Davis left the Raiders after being named AFL Commissioner, promoting assistant coach John Rauch to head coach. Two months later, the league announced its merger with the NFL. The leagues would retain separate regular seasons until 1970. With the merger, the position of commissioner was no longer needed, and Davis entered into discussions with Valley about returning to the Raiders. On July 25, 1966, Davis returned as part-owner of the team. He purchased a 10% interest in the team for $18,000, and became the team's third general partner – the partner in charge of football operations.