Incredibly, the 33-year-old full-back was spotted sprinting towards the pitch as the quarter-final second leg began without him.
The match will be played at Barcelona's Nou Camp. Iniesta, though, believes they are more than capable.
"We need to try and score as soon as possible and see how the game unfolds, be patient and know how to suffer, how to push when needed and try to make the most of our opportunities", Iniesta said during the pre-match press conference.
Monaco has already played 53 games in all competitions this season and fatigue is starting to take its toll on the French league leaders.
"Right until the 95th minute we have to be united", he said. 3-0 will take it to extra-time, 4-0 would be ideal, but just one Juve goal would leave Barca needing five. There is only one way to read it.
"We have to score goals, and the earlier, the better".
"The first leg was a bad result for us".
They all wore black pants as they had a tour of Nou Camp where they will be facing Barcelona. They are not the team that surrenders five goals. "We have another chance to do something historic".
"Now is not the moment to talk about it, though, with the focus on Juventus and everything we're playing for".
Long-term absentees Rafinha and Aleix Vidal will be the only ones to miss the game on the home side. Barcelona welcome Juventus to the Camp Nou later today for the second leg match and after their heroics in the previous round against PSG, the Blaugrana can not be ruled out just yet.
"The team played in Turin without any confidence, and that made us soft".
"We need to keep our heads and find a way to score at least once".
However, inspired by Johan Cruyff's double and an 87th minute penalty from Carles Rexach, Barca levelled the scores on aggregate.
Ahead of the game, Higuain told Juventus website: "I don't know whether our 3-0 lead will be enough". Barca was the first team in European history to overcome a 4-0 first-leg CL deficit.
As another good omen for Barca, they also beat Juventus on route to the final that year.
The sides clash at the Santiago Bernabeu in Tuesday's second leg with the Germans looking to become just the third side to overturn a first-leg home defeat to win a Champions League tie.
A contribution from Lionel Messi would be helpful, too.
The Blaugrana were able to overturn a 4-0 deficit to Paris Saint-Germain in the round of 16, however the Bianconeri provide an entirely different challenge.