John Harbaugh has identified Brian Cushing as the key player in the Houston Texans' defense.
The linebacker, who missed the majority of last season with a serious knee injury, has made 16 tackles, 1.5 sacks and an interception in the first two games of the season.
The Baltimore Ravens head coach told reporters: "Certainly a healthy Brian Cushing is key for them. He's an enforcer in the middle, [and] he's a really good run stopper, one of the best.
"He's one of the best blitzers in the league, especially when he adds on, but also when he's a primary blitzer.
"They do a lot with him and JJ [Watt, the 2012 defensive player of the year] in the run game off the strong side of the defense there. They cause a lot of problems for everybody, and [it's] not just those two guys."
The AFC South side will take on the Super Bowl Champions tomorrow.