The Catalans were shockingly eliminated from the competition on Tuesday, losing 3-0 at Roma in the second leg of their quarter-final tie.
Roma advanced to the semi-final via away goals in a 4-4 aggregate result after losing the first leg 4-1 at Camp Nou last week.
The 33-year-old started for Barcelona and after being taken out on 81 minutes, could only watch on from the bench as Kostas Manolas scored a dramatic late goal to send Roma though.
Iniesta's future with Barcelona is up in the air, with the club legend setting an April 30 deadline to decide on his future.
With a big-money offer from China on the table, Iniesta admitted that Tuesday could have been the final time he wears a Barcelona shirt in the Champions League.
"It's not the time to make any proclamations, we're all hurting," Iniesta said in the mixed zone following the game.
"Was it my last game in the Champions League? It's possible."
If Iniesta's Champions League career is indeed over, he finishes having lifted Europe's top club prize four times: in 2005–06, 2008–09, 2010–11, and 2014–15.