The former Blues captain says the midfielder is the ideal symbol of leading by example.
Terry told The Sun: “He probably doesn't think, 'I'm a leader here', but he's leading the group with his standards - 'This is the standard you probably need to get up to. You need to get as fit as me.'
"From afar people look at captains and leadership as if you've got to be that big vocal guy, screaming, shouting, barking orders. I think it's very different now.
"A lot of players now do it in the way they're playing. He certainly falls under that category. Cole's probably leading the way he likes to lead.
"He's been incredible for us. He's taken a lot of the heat in terms of our dip, but also in terms of our first part of the season.
"It was probably all him, with his goals, contributions, work rate. Everything Chelsea were doing well revolved around him.
"Teams have obviously identified that he's the big threat and there needs to be a real focus."