Mason has Sunday’s Carabao Cup Final against Manchester City around the corner, but is still likely to go with his strongest side to build confidence and momentum ahead of the Wembley showpiece.
The absence of Harry Kane, missing with an ankle injury, could see Mason start Heung-min Son up-front, freeing up space for Dele, Bale and Giovani Lo Celso in the front four.
Mason’s defensive selections will be intriguing after Mourinho all but lost confidence with all his senior centre-backs.
The 29-year-old is likely to stick with Joe Rodon, who impressed in the death-throes of Mourinho’s reign, and the Welshman could play alongside experienced Belgian Toby Alderweireld.
Harry Winks will be more confident of minutes now his former teammate is in charge, but Tanguy Ndombele and Pierre-Emile Hojbjerg were two of Mourinho’s more consistent players and are likely to keep their places in midfield.
Matt Doherty is fit again but unlikely to start, but Ben Davies joins talisman Kane on the sidelines.
Tottenham predicted lineup (4-2-3-1): Lloris; Aurier, Alderweireld, Rodon, Reguilon; Hojbjerg, Ndombele; Bale, Dele, Lo Celso; Son.
Where: Tottenham Hotspur Stadium, Wednesday April 21, 18.00
Spurs from: Lloris, Hart, Austin, Aurier, Tanganga, Doherty, Reguilon, Dier, Alderweireld, Rodon, Sanchez, Winks, Ndombele, Lo Celso, Dele, Bergwijn, Lamela, Lucas, Son, Bale, Vinicius.
Injury list: Davies (calf), Kane (ankle)
Last meeting: Saints 2-5 Spurs