Write a question about the following article: Hoping to add to a four-game winning streak, the Broncos returned home for an AFC West rematch with the San Diego Chargers. The Chargers grabbed the lead in the first quarter, with safety Eric Weddle returning an interception off Broncos' quarterback Peyton Manning 23 yards for a touchdown. The Broncos responded early in the second quarter, with Manning connecting on a 13-yard touchdown pass to wide receiver Demaryius Thomas. On the Chargers' next possession, quarterback Philip Rivers was intercepted by Broncos' safety Jim Leonhard deep in Chargers' territory. However, the Broncos had to settle for a 19-yard field goal by placekicker Matt Prater. On the first play after the two-minute warning, Broncos' linebacker Nate Irving blocked Mike Scifres' punt, and on the next play, Manning threw a 31-yard touchdown pass to wide receiver Brandon Stokley, giving the Broncos a 17-7 lead. The first points of the third quarter came from the Chargers, with linebacker Shaun Phillips sacking Manning in the end zone for a safety. After linebacker Wesley Woodyard recovered a Rivers' fumble deep in Chargers' territory, the Broncos increased their lead, with Manning throwing a 20-yard touchdown pass to wide receiver Eric Decker. However, the Chargers responded late in the third quarter, with Rivers connecting on an 8-yard touchdown pass to wide receiver Danario Alexander. A pair of field goals by Prater in the fourth quarter&#8212;from 30 and 32 yards&#8212;gave the Broncos a 30-16 lead with 4:14 remaining in the game. The Chargers tried to rally, with a 21-yard touchdown pass from Rivers to Alexander with 1:24 remaining. However, the Broncos' recovered the onside kick, and subsequently ran out the clock. With the win, the Broncos earned their first season sweep of the Chargers since 2005, and snapped the Chargers' three-game winning streak in Denver. Nate Irving's block of a Mike Scifres' punt marked the first time since 2007 that the Broncos' special teams blocked a punt. This was the only game during the 2012 season in which the Broncos wore their alternate navy blue jerseys. Running back Willis McGahee suffered a ruptured MCL and compression fracture in his right knee during the second quarter, when his knee was hit by the helmet of Chargers' cornerback Quentin Jammer. On November 21, McGahee was placed on the injured reserve/designated for return list.

Question about the article:
How many quarters did McGahee play in?