[4] Butt's form with Thornycrofts once again attracted the attention of Bert Lee, now Southampton's trainer, and in August 1920 he re-joined the "Saints" as a full-time professional.
[3] Butt spent two seasons with Southampton, during which period he made 18 first-team appearances – he was prevented from playing more regularly by the form of the established half-back line-up of Bert Shelley, Alec Campbell and Bill Turner, and was only called into the first team if one of these was injured.
His longest run in the side came at the end of the 1920–21 season, when he played 11 matches at left-half, taking over from Turner, who had dropped to right-back as replacement for the injured Tom Parker.
Butt remained at Dean Court for a further four years, rarely missing a match in the first three Football League seasons, before retiring in the autumn of 1927.
He died on 3 December 1993, shortly before his 100th birthday;[2] at the time of his death, he was the last surviving player who signed for Southampton when they were still in the Southern League.