I'm not sure that Iniesta was even burnt out when his best run of form by far was in the final 5-6 matches of the season when he should have been most fatigued.
He played good but generally tend to tire out near the end. He was notably overused during the hectic February schedule, barely never had any full rests and played more in away matches than home games.
90 mins Away against Espanyol 04/02
65 mins Away against Valencia 08/02
28 mins Home against Getafe 11/02
63 mins Away against Eibar 17/02
90 mins Away against Chelsea 20/02
75 mins Away against Las Palmas 01/03 ( Very wierd decision to bench Coutinho and Dembele)
And finally got injured against Atletico 04/03
The only full rest he had was against Girona, which was a home game as well. It was really wierd for EV to keep playing Iniesta in poor pitch conditions, and usually for full matches and you could see these games are so packed together.
When he was back from injury, he played against Chelsea, and then immediately started with no rest against Bilbao. Got called up for international duty, and then played 85 mins for both Sevilla Away and Roma (Home). Still played a little against Leganes and then the Roma away match he was quite gassed and didnt perform as well.
In fact, the whole team looks fatigued as hell, and then a really wierd decision to bring on Gomes during a crucial match like this. Then again if one can trust Gomes in a big match, then theres really no excuse like there is no "alternative". This doesnt just apply to Iniesta, even for Pique, Suarez and Rakitic, Roberto are overplayed, and u have players just sitting on the bench.