Giants left tackle Luke Petitgout broke his leg against the Chicago Bears last month, and it looked like trouble for Eli Manning. Aging veteran Bob Whitfield replaced Petitgout, and Bears defensive end Alex Brown had a field day. Matched up against the rusty Whitfield, Brown sacked Manning twice, forcing him to fumble both times, and hit Manning as he passed to force an interception.

The Giants lost that game and all three games since then, so no one will question Petitgout’s importance. But a strange thing has happened since that Bears game: Opposing defensive ends haven’t been able to get to Manning. In fact, in the three games since that loss to the Bears, Manning has thrown 105 passes and only been sacked once, and the Giants’ last two games mark the first time in his career Manning has ever made it through two consecutive games without being sacked.

Part of the reason is that Whitfield has improved since that terrible performance against Chicago. The 35-year-old Whitfield has been almost exclusively a backup in his two years with the Giants, and when he took Petitgout’s place against the Bears, he looked like a player who hadn’t expected to take the field. But Whitfield has lasted 15 NFL seasons for a reason. He’s not the most physically gifted of blockers, but he has shown in three games against the Jacksonville Jaguars, Tennessee Titans, and Dallas Cowboys that he can at least fill in for Petitgout competently.

Giants offensive coordinator John Hufnagel and the rest of the coaching staff have also helped protect Manning since Petitgout went down by changing the team’s protection schemes and pass patterns. Manning hasn’t had Petitgout protecting his blind side, but he has had more blockers to keep him from feeling pressure and more outlets for quick passes to throw when the protection breaks down.

Part of the protection comes from backup lineman Rich Seubert, who plays regularly as a blocking tight end. The Giants usually put Seubert on the field on running downs, but when the Giants pass with Seubert on the field, Manning gets better protection from six offensive linemen than he would from five. Fullback Jim Finn has also played a big role in keeping Manning upright. Finn is almost like a sixth lineman himself — he blocks very well but has caught only three passes this year and hasn’t had a rushing attempt in two years. When Finn is in front of running backs Tiki Barber or Brandon Jacobs, the Giants usually run, but in recent weeks Finn has increasingly taken the field on passing downs, where he excels at picking up blitzing linebackers. Although Finn sometimes runs pass routes, he doesn’t have the speed to be much of a threat catching the ball, and he dropped a pass against Dallas on Sunday.

Manning is also protecting himself by throwing shorter passes in the last four weeks. He averaged 11.6 yards a completion heading into the Chicago game, but he has averaged just 10.2 yards a completion since then. Shorter passes take less time to develop and give the defense less time to get to the quarterback.

The changes to the offense have kept Manning upright, but that doesn’t mean they’ve made him better. Although Manning had his best game of the year Sunday against Dallas, that followed back-to-back mistake-filled performances against Jacksonville and Tennessee. Manning needs more games like Sunday’s for Big Blue to make the playoffs.

The Giants’ next game comes against another team, the Carolina Panthers, fighting for a playoff spot, and Carolina’s pass rush will present a different kind of challenge than the Giants have faced in their previous games without Petitgout. Most defenses line up their best pass rusher against the left tackle, meaning Whitfield has the hardest task of any offensive lineman. But the Panthers’ best pass rusher, Julius Peppers (who leads the league with 11 sacks), lines up on the other side of the line. On Sunday he’ll play across from Giants right tackle Kareem McKenzie, and when the Giants use Finn and Seubert in pass protection, their main priority will be helping McKenzie keep Peppers away from Manning. That means Whitfield will have to take on the Panthers’ other defensive end, Mike Rucker, by himself.

Offensive linemen are rarely noticed unless they give up a sack or get called for a penalty. Whitfield was noticed once against Dallas, when he committed a dumb personal foul, headbutting Cowboys defensive end Jason Hatcher. That was a big mistake on a team that has made far too many mistakes the last few weeks, but after three games without their starting left tackle, the Giants have to be pleased that no one seems to notice their offensive line.

Mr. Smith is a writer for FootballOutsiders.com.