Arsenal take on the league champions at the Bird's Nest in Beijing in a re-run of last season's FA Cup final, a game which the Gunners won 2-1.
Chelsea will play Arsenal again before the start of the new league season, the London clubs facing off at Wembley in the Community Shield, and Wenger says Saturday's meeting is important.
"It's difficult to predict, but it's a friendly between Chelsea and Arsenal," the Frenchman told reporters on Friday. "That means it's not really a friendly.
"There is always some desire to have superiority. We played them in the FA Cup, we play them in the Community Shield and then again early in the season."
A sickness bug has caused selection issues for Wenger during his side's pre-season tour of Asia, which included a penalty shoot-out victory over Bayern Munich in the International Champions Cup.
"[Theo] Walcott might not play tomorrow," Wenger said. "Today we had 21 players fit. Walcott was not ready, but it's nothing major."
France international Laurent Koscielny should be able to take his place in the Arsenal back line, however, after shaking off an injury.
"My back is better," the centre-back said. "Today I trained and I'm OK, not 100 per cent but OK. We will see tomorrow."