The former England captain and 2005 Ashes hero will act as head coach for the Headingley-based side this summer.
Oxford Harlequins have been promoted into the National League after beating Banbury RFC to win the title with two matches to go.
Sir Jim Ratcliffe has signalled an end to Manchester United spending huge sums on superstar names by insisting the club’s focus should be on unearthing the “next Kylian Mbappe” and the “next Jude Bellingham”.