Guardiola: Stopping Juninho free kicks key
The Brazilian stunned Barca early in the first leg of the last 16 tie in France with a trademark strike that sailed over goalkeeper Victor Valdes, before Thierry Henry equalised in the second half.
"It will be important not to give away free kicks around the box," Guardiola said at a news conference on the eve of Wednesday's return at the Nou Camp, adding that Barca would try to keep the ball in the Lyon half.
"The best form of defence is attack," the former Barca and Spain midfielder said. "I think they will wait until we lose the ball and try to hit us on the break."
The Primera Liga leaders come into the match having stretched their advantage over Real Madrid to six points with a 2-0 home win over Athletic Bilbao on Saturday.
Lyon's 2-0 defeat at Lille at the weekend chopped their Ligue 1 lead down to one point from six two weeks ago and their woes have been compounded by injuries to key players.
At an earlier news conference, Barca striker Samuel Eto'o said he was unconcerned about his recent lack of goals and hoped his 28th birthday on Tuesday would bring the team luck.
"I have scored a lot already this season and when they don't go in for a few matches there is no point making a drama out of it," said Eto'o, who hasn't netted in four matches since his league double against Real Betis on February 14. "I am calm."