Quins, who earned a surprise 32-8 victory in Nantes, welcome the French side to Twickenham Stoop for the reverse fixture this weekend.
O'Shea now wants his team to take the game to Racing as they look to progress from Pool 4.
"We played excellently, with a huge amount of intensity," he told Sky Sports News. "We need to start this match with the same amount of intensity. We have to move the ball around with pace. It if becomes a set-piece game then it becomes more suited to them.
"We have to keep the tempo up because if you go toe-to-toe with a heavyweight and you are a light-weight you are going to get beaten. We have to keep the ball on the move."
The English side head into the match in second place in Pool 4, three points behind leaders Clermont Auvergne.