The Scudetto holders stand on the verge of claiming a fourth-successive title in Allegri's first campaign at Juventus Stadium, currently topping the table by 12 points.
However, eight successive wins has seen Lazio burst into the picture at the top of the table and Allegri will give his full focus to the meeting with Stefano Pioli's men rather than Wednesday's UEFA Champions League quarter-final second leg against Monaco.
"It's a Scudetto game," said Allegri. "We have a points advantage, but we are coming to a difficult cycle of games.
"From here to the game with Sampdoria [matchweek 34] will decide the season.
"I'll be deploying my best team, as always.
"Tomorrow's game is the most important one, we'll see about the one on Wednesday, and then the one next Sunday.
"We must focus on what we have to do, because we haven't won anything yet, so we have to think exclusively about our objectives.
"Lazio are having an extraordinary season.
"Since the first half of the season, Lazio have gained greater confidence in their abilities.
"Nobody would have predicted they'd do so well at the start of the term. We have a points advantage over Lazio but also five difficult games to follow."
Andrea Pirlo is expected to make his Serie A return after featuring in Juve's 1-0 first-leg win over Monaco in midweek.
Bizarre Jose Mourinho statement aims to pre-empt punishment after Fenerbahce boss clashes with Galatasaray counterpart
'Andy Robertson has a decision to make as a player, where you either roll your sleeves up and give someone great competition or you accept decisions and say that your time is done.' Alan Shearer on the conundrum facing Arne Slot's Liverpool
