Rumours emerged on Sunday (AEDT) that the Argentina international will hold a news conference next week to confirm he will not resume his playing career.
Aguero has not played a game since the 1-1 draw with Deportivo Alaves at Camp Nou on 31 October (AEDT), during which he was substituted after feeling dizzy and suffering apparent discomfort in his chest.
😬 It was a troubling sight to see @aguerosergiokun clutching his chest during @FCBarcelona's draw with @Alaves, and the club has confirmed he underwent a cardiac exam at hospital after leaving the field early. More here 👉🏻 https://t.co/p8Xr92MRCm | #LaLiga #BarcaAlaves pic.twitter.com/j5idjp9LVn— beIN SPORTS (@beINSPORTS_AUS) October 30, 2021
Barca later confirmed he would be unavailable for three months while doctors monitored a suspected cardiovascular problem. The 33-year-old tweeted on 13 November to insist he was "always positive" amid suggestions he would not be able to continue playing.
Xavi, who oversaw a 1-0 win over Espanyol in his first match in charge, insisted it was not true that Aguero's retirement was confirmed.
"What's come out isn't true," Xavi said. "I spoke with him, he's calm and happy. I asked him to come back when he was feeling okay."
Memphis Depay's penalty sealed Barca's victory over its city rival, although it rode its luck in the closing stages as Raul de Tomas twice hit the post and Landry Dimata headed a glorious chance for an equaliser wide.
"I'm very happy with the three points and the effort of the players," Xavi said. "We're not in the best of spirits and Espanyol created a lot of problems for us. And we deserved the luck with the posts.
"I'm happy, and I think it was a deserved victory. What couldn't fail, which was the attitude, didn't fail."
The result moved Barca to within eight points of LaLiga leader Sevilla, which earlier drew with Alaves, after 13 LaLiga matches.
While a title shot appears unlikely at this stage, Xavi – an eight-time league champion in a glittering playing career with the club – saw no reason to discount a challenge for the trophy.
"We're far away but there are matches left. I'm optimistic and why can't we fight for the title?" he said.