This is the sixth installment of a nine-part series that reviews every 49ers player and position group.After seeing how Stanford offenses used its tight ends under coach Jim Harbaugh and offensive coordinator Greg Roman, big things were expected from Vernon Davis and Delanie Walker in the 49ers' passing game. However, it did not work out that way through most of the season. Both Davis and Walker had their lowest production since 1998 2008, when then-offensive coordinator Mike Martz virtually eliminated the tight end from the offense. But things picked up late for Davis, who became the team's top receiving threat -- really, their only receiving threat -- in the playoffs. Grade: BVernon Davis -- After two seasons with more than 900 yards receiving, Davis' production took a step back in the regular season. He struggled mightily to learn the new 49ers system, and admittedly became frustrated. But late in the season, it seemed to click for him. He averaged 42 yards receiving in the 49ers' first 13 games. In his final five games, including the playoffs, Davis averaged 107 yards receiving. He has never been finer than in the two playoff games, catching 10 passes for 292 yards and four touchdowns. Davis played more than 95 percent of the team's offensive snaps during the season, and he once again excelled as a blocker.Delanie Walker -- When Walker caught six passes for 69 yards on Nov. 13 against the New York Giants, it figured to be the start of a larger role in the passing game. But Walker finished the season without another catch in the six games before sustaining a fractured jaw that kept him out of action for a month. He returned to action and caught two passes for 36 yards in the NFC Championship Game against the Giants. Walker made major improvements as a blocker this season. He threw key blocks on Detroit defensive tackle Ndamukong Suh to spring big runs in the 49ers' win. Walker finished the regular season with just 19 catches for 198 yards and three touchdowns in 15 games.Justin Peelle -- The 10-year veteran was added to the 53-man roster after the first game of the season as a blocking specialist. He did what he was brought in to do, and his play time saw a bump late in the season after Walker's injury. He was used almost exclusively in short-yardage situations. He caught just one pass for 19 yards during the regular season.Nate Byham -- His season ended before it began when he sustained a torn ACL in his left knee during training camp. Byham spent the entire season on injured reserve. His rehabilitation is on schedule. Although he said he believes he would be ready to participate in minicamps and organized team activities, Byham said there is no reason to rush it. He fully expects to be ready to compete for a roster spot in training camp.