Tuilagi is serving a five-week ban imposed by the Rugby Football Union after he was cited for punching Northampton's England wing Chris Ashton during Tigers' play-off victory over Saints a fortnight ago.
The only Leicester changes from that game see Smith moved to outside centre, with Horacio Agulla filling Smith's normal wing slot.
England prop Dan Cole and Rugby Players' Association players' player of the year Thomas Waldrom both have to be content with places on the bench.
Neil de Kock, meanwhile, has seemingly won the coin-toss to decide who will wear Saracens' number nine shirt in the final.
South African de Kock and England international Richard Wigglesworth have alternated in the starting XV all season, and it was revealed they would toss a coin to decide which one of them would be on replacement duty at Twickenham.
"Neil and I came up with the idea of tossing a coin because we have played in strict rotation all season," said Wigglesworth, earlier this week.
"It seemed the simplest way and (Saracens rugby director) Mark (McCall) agreed."
The scrum-half change is Saracens' solitary switch from the team that beat play-off opponents Gloucester 12-10 at Vicarage Road.
Teams for Leicester v Saracens, Aviva Premiership final
Leicester: S Hamilton; H Agulla, M Smith, A Allen, A Tuilagi; T Flood, B Youngs; M Ayerza, G Chuter, M Castrogiovanni, S Mafi, G Skivington, T Croft, C Newby (capt), J Crane.
Replacements: R Hawkins, B Stankovich, D Cole, E Slater, T Waldrom, J Grindal, J Staunton, B Twelvetrees.
Saracens: A Goode; D Strettle, C Wyles, B Barritt, J Short; O Farrell, N de Kock; M Stevens, S Brits, C Nieto, S Borthwick (capt), M Botha, K Brown, J Burger, E Joubert.
Replacements: J George, R Gill, P du Plessis, H Vyvyan, A Saull, R Wigglesworth, N Mordt, N Cato.
Referee: Wayne Barnes (Rugby Football Union).
Assistant referees: Dave Pearson and Stuart Terheege (both RFU).
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