Lovren left Liverpool for Zenit last year.
He told Sport-Express: "In England, the intensity of the game is different. In the Russian Premier League, players have a lot of time and space. And in England you get the ball from the goalkeeper and send it straight ahead.
"Zenit has a quality squad. But we're back to work ethic again. You have to fight in every match. It happens that a weaker opponent remains in the minority, and you immediately think about winning. But this is not the case.
"In the Premier League, you need to give 100 percent. If my teammates fight in every game, then Zenit will have a chance to catch the middle of the Premier League table."