Barcelona forward Lionel Messi believes it would be "screwed" if Manchester City's players were banned from playing in the UEFA Champions League for two years.
Last week City were hit with a two-year ban from European competition by UEFA for "serious breaches" of Financial Fair Play regulations following an investigation.
City, who were accused of "overstating sponsorship revenue" between 2012 and 2016, have denied any wrongdoing and intend to appeal the sanctions at the Court of Arbitration for Sport.
However, should the ban stick, it would cast doubts over the futures of players such as Raheem Sterling, Kevin De Bruyne and Messi's close friend Sergio Aguero.
"It is surprising because nobody thought that such a thing could happen, so powerful," Messi told Mundo Deportivo.
"Paris [Saint-Germain] paid a fine or I don't know how it went. If in the end City does not play in the Champions League for what it is, with the players, the club, and the money it spends, it will be weird."
Messi was then asked about the possibility of his compatriot Aguero wanting to join him at Camp Nou should the ban be upheld.
"If City do not enter the Champions League there are many players that may look for an exit, or maybe not," Messi said.
"The Champions League is very attractive so two years without playing it can be screwed."
City face Real Madrid in the last 16 of this season's competition, with their Premier League rivals Liverpool having already lost to another club from the city in their first leg.
Atletico Madrid became just the third team to defeat the Reds this season when they claimed a 1-0 success in Spain on Tuesday, not that Messi was surprised by the La Liga side's performance.
"The truth is, no," he said.
"On the day of the draw we talked in the dressing room that it would be very close because Atletico competes a lot in this competition.
"In duels of two matches they are very strong and they showed it again, that they will compete and they will be there."