Last year at Wimbledon, he was hobbled by a blister on his foot and couldn't play his normally attacking style of tennis. Frustrated by not being able to perform in the moment, he put a towel over his head during a changeover and broke down in tears. He went on to lose in straight sets.
There were no tears after his five-set loss to Federer in the Australian Open final on Sunday -- at least, none from Cilic -- but the big-serving Croatian player was frustrated nonetheless. This time, by the decision to close the roof at Rod Laver Arena before the match because of the extreme heat in Melbourne.
The tournament referee made a late call to close the roof, and Cilic said it was tough to acclimatize to playing indoors after practicing outdoors earlier in the day when the temperature reached a high of 38 Celsius (100 Fahrenheit).
"I have to say that decision, could it have been different? I guess so. I think that it was just little bit difficult to adjust, especially the beginning of the match," Cilic said. "With the roof closed, it was way, way cooler than I expected. That was very, very difficult, especially for the final to be in that kind of a situation."
Cilic did have a poor start to the match, getting broken in his first two service games and dropping the set in just 24 minutes. Afterward, he wasn't sure if the decision to close the roof gave Federer an advantage, but it clearly threw off his game.
"I had a slow start in the match," he said. "Then catching up most of the time."
After Cilic caught up and forced a fifth set, he had two chances for an early break in the first game that would have given him the lead and continued his momentum. But he made two errors and let the chances slip away, then dropped his own serve twice as Federer ran away with the set.
"I wasn't sure if it was good for me or not, to play under the roof or not," Federer said. "Of course, I backed myself in sort of indoor conditions. This is where my first success ever came. I do think back that usually when I play indoors, it's good for me.
"But I didn't mind the heat, to be honest. I thought maybe for a bigger guy like Marin, maybe it's also going to slow him down faster throughout the match. At the end, it's not my decision. They kept me posted along the way."
Still, Cilic was pleased just to have made his third major final and coming oh-so-close to getting a second Grand Slam trophy (he won the 2014 US Open). He also believes he's closing the gap with the top players in the men's game -- the so-called Big Four of Federer, Rafael Nadal, Novak Djokovic and Andy Murray.
Literally speaking, he's closing the gap in the rankings, rising to a career-high of No. 3 next week, just behind Nadal and Federer, respectively. But Cilic thinks he's learning how to play better against them, too.
His record against the Big Four is still a lowly 7-40 combined, including now 1-9 against Federer. But Cilic did get a win over Nadal when the Spaniard was forced to retire with a leg injury while trailing 2-0 in the fifth set of their quarterfinal in Melbourne. And then he took Federer to a fifth set.
"My ultimate goal is to reach No. 1," Cilic said. "Even in these last one or two years, the progress that I did is big. Last year, I improved a lot in different areas. Now in these last couple months, I improved even more. So that gives me big confidence."
He realizes it will be tougher to make deep runs at majors when the injured Djokovic and Murray return to full strength, but he's ready for the challenge.
"No. 3 feels and looks amazing," he said. "I am continuing to improve. Big time ahead for me."
Information from The Associated Press was used in this report.