"It's not just about Costa, they have Cesc Fabregas, Eden Hazard, Oscar - a lot of good players - and it [Stamford Bridge] is a difficult place to go, especially when they are playing with a lot of confidence," said Potters midfielder Adam.
"But hopefully we can go there and cause them problems. You can find chinks in the armour. We always make a point before the games of looking for the weaknesses in teams and what we can exploit.
"I don't think Costa's a bully. He's a top striker, a powerful striker, similar to Didier Drogba when he first came over.
"He holds the ball up really well for them, a strong centre. But Ryan Shawcross knows how to play against him and he has done well when he has played against him in the past."