"More beautiful than winning one Champions League is to win two in a row, the same goes for the FA Cup," Dias said, explaining City's "motivation could not be any higher".
City coach Pep Guardiola said midfielder Bernardo Silva was in line for a return from injury and would take the flight to Germany, along with defender John Stones.
"They feel better, Bernardo better than John," Guardiola said.
"They're back, which is good news for us."
City's flight was delayed due to weather conditions, but the English champions are still expected to arrive a day before the game.
Guardiola said defender Josko Gvardiol, who moved from Leipzig to City in the summer, was "settling in well" and had already shown his "tremendous quality".
The last time the two teams met, City thrashed Leipzig 7-0 in the second leg of their last 16 tie, but RB coach Marco Rose said the thrashing was "history".
City's rampant victory in their home leg of last season's clash, with Erling Haaland scoring five goals inside an hour, helped propel them towards a first Champions League title.
"It wasn't part of the preparation for the game, because it's history," Rose said in Leipzig on Tuesday.
"Everything came together for them in that match and of course we were hugely dissatisfied with the size of the result.
"But we're in a new season and we're doing pretty well right now."
Leipzig ready to 'suffer'
Leipzig have won seven of nine games in all competitions this season and come into the match fresh off a 2-2 home draw with German champions Bayern Munich.
Rose said his side could draw positives from the home leg against City last season, where Leipzig fought hard to draw 1-1.
"We know that we played very well at home and for that to happen again tomorrow, we have to run a lot and we have to suffer."
Rose replied "yes" when asked if City were the best side in the world.
"But that doesn't help us and it doesn't help City," he added. "It's football and we will play 11 against 11.
"We know City's quality. We will need a top performance and a slice of luck."
City come into the match in a rare run of poor form, having lost two games in a row for the first time since January.
Midfielder Kevin De Bruyne is a long-term absentee for City, but Rose highlighted the other options available to them.
"Even when De Bruyne and Bernardo Silva are missing, then in comes (Mateo) Kovacic, then in comes Phil Foden, who has developed really well," he said.
Rose added he was looking forward to seeing Gvardiol again, calling the Croatian centre-back "a great player and a great guy".
The Leipzig coach confirmed wing-back Benjamin Henrichs will miss the clash through injury, while Spanish international forward Dani Olmo is also ruled out as he continues his recovery from injury.
Former Chelsea forward Timo Werner is however set to make a return from a back complaint.
