The Argentine left Manchester City on a free transfer in the summer and joined compatriot Lionel Messi at the Camp Nou.
However, shortly after his arrival, it become clear that Messi wouldn’t be staying in Barcelona for too much longer.
And as Messi left for Paris Saint-Germain, Aguero picked up an injury that would rule him out for the start of the season.
Barcelona have made a pretty wretched start to the season and have already sacked manager Ronald Koeman.
But Aguero is now back fit and will be looking to help Barca out of this difficult situation.
He started their match against Alaves on Saturday evening - the first game under the interim boss, Sergi.
However, Aguero only lasted 41 minutes and his substitution is shrouded in mystery.
The striker appeared to be struggling to breathe and there was immediate concern from medical staff.
Aguero was able to walk off the pitch without the help of a stretcher but it was certainly a concern.
Aguero suffers from 'breathing issues'
He was replaced by Philippe Coutinho.
We just hope it’s nothing too serious for Aguero and he’s back on the pitch soon enough.
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Ahead of his first match in charge of Barca, Sergi insisted that he just wants to get the 'happy faces' back at the club.
"The first thing is to get the happy faces back," he insisted. If we get the players back and recover the idea of attacking football, it will help us," he commented.
"I'm a winner and I like winning players. We all have to turn the situation around. Depending on what we see, we will intervene to a greater or lesser extent."News Now - Sport News