The Lions were the first victim of Bears receiver Alshon Jeffery’s recent tear. In the past five games, the second-year wide receiver has 25 catches for 517 yards and three touchdowns, starting with five catches for 107 yards and a score in the Week 4 game at Ford Field. And with Brandon Marshall on the opposite side, Jeffery has given the Bears one of the NFL’s most dangerous receiving duos. “He’s about 8 feet tall, so that helps him,” Lions defensive coordinator Gunther Cunningham said of the 6-foot-3 Jeffery. “He’s really dangerous down in the red zone. “He does a good job blocking, and overall it’s really made them a much, much more productive offense.” Jeffery has 621 receiving yards this season, and Marshall has 647 yards and six touchdowns. Marshall said on a conference call with Detroit reporters that their numbers show they’re the best duo in the NFL. Denver’s Demaryius Thomas and Eric Decker are the only other teammates with more than 600 yards each. With Marshall standing 6-4, the duo can give smaller cornerbacks some problems, but Lions cornerback Rashean Mathis expects his group to handle the tall receivers. Mathis is 6-1, Darius Slay 6-foot and Chris Houston 5-11. “We know they’re big. We know they’re strong,” Mathis said. “We’re not the smallest ourselves. We compete. That’s what we do. That’s why we’re defensive backs.