Mason has made two changes to the Spurs team that lost at Wembley, with Alli and Bale coming in for Harry Winks and Lucas Moura.
Alli has not started for Spurs since their 3-0 Europa League defeat against Dinamo Zagreb on March 18 and the midfielder has not started in the Premier League since March 4.
The trio of Alli, Bale and Heung-min Son support Harry Kane.
Confirmed Spurs XI: Lloris, Aurier, Alderweireld, Dier, Reguilon, Hojbjerg, Lo Celso, Alli, Bale, Kane, Son.
Subs: Hart, Doherty, Sanchez, Winks, Lamela, Sissoko, Bergwijn, Moura, Ndombele.
Confirmed Sheffield United XI: Ramsdale, Bogle, Baldock, Egan, Basham, Stevens, Fleck, Norwood, Osborn, McGoldrick, Brewster.
Subs: Foderingham, Lundstram, Berge, Mousset, Lowe, Burke, Jagielka, Robinson, Gordon.
Venue: Tottenham Hotspur Stadium, Sunday, May 2, 19.15pm.
TV: Sky Sports
Referee: Andre Marriner