The 29-year old broke his jaw in Kawasaki's 2-0 defeat to South Koreans Seongnam Ilhwa on matchday 1 and his midfield partner Hiroyuki Taniguchi knows how big a loss the Japan international will be for tonight's clash with Chinese champions Beijing Guoan.
"The hole left behind due to Kengo's absence is huge," he admitted.
"But we should fill that hole with our teamwork and we want to get through this group stage and qualify for the next stage, by all means."
Kawasaki coach Tsutomu Takahata understands just how dangerous the Chinese outfit can be and was erring on the side of cautious heading in to the contest.
"Beijing have good physical players with height and power, and have a solid defence that can hold out and launch counter-attacks," he said.
"They work hard defensively and offensively.
"The best way to play against that would be to play our brand of football, without becoming passive in attitude, as this is our home game. We want to break through their defence and score while nullifying their counters.
"They have China national team players, foreign players and former China internationals. We have to be careful about all of them. There's no weakness in their side, that's what I feel."