Aguero, already hampered by injury problems this season, has
been self-isolating after falling ill with the virus.
City's record scorer has made just three starts in all
competitions this term and hasn't played since January 3.
After testing negative for the virus, Aguero can now come
out of quarantine.
But the 32-year-old has not yet restarted full training as
he slowly works his way back to fitness.
"He is still not training on the field. He started to
move a little yesterday but he will need a few weeks to come back,"
Guardiola told reporters on Tuesday.
"He is negative, this is the most important thing. He
is healthy again and now he will come back again. As the top scorer it is
important for us to have him back."
City will travel to Burnley on Wednesday in fine form after
a club record 12 successive wins.
Eight of those victories have come in the Premier League,
lifting Guardiola's side to the top of the table, three points clear of
second-placed Manchester United.
That represents a considerable turnaround after an
indifferent start to the campaign in which City dropped points in five of their
opening eight games.
After a trip to Turf Moor, City face title rivals Liverpool
at Anfield on Sunday.
But Guardiola refused to read too much into City's blistering
streak and is focusing only on keeping the good run going against Burnley.
"Six weeks ago we were not contenders for anything, six
weeks later we are contenders. Everything can change so quickly,"
Guardiola said.
"We can drop five points in two games in three days. It
has happened to other teams so it can happen to you."