Vikings offensive coordinator Bill Musgrave called a play designed to get John Carlson free down the sideline as Christian Ponder's primary target.

At the snap, Carlson cut through traffic near the line as Ponder gave a quick pump fake to Percy Harvin on a screen. The plan got scuttled, however, when San Francisco linebacker Patrick Willis smartly recognized Carlson's intentions and smothered him in man coverage, something the Vikings weren't expecting. Ponder countered by tucking the ball and running 23 yards through the teeth of the 49ers defense for a touchdown in the second quarter of the Vikings' 24-13 victory last week.

That read-and-react moment by Ponder provided another measurable sign of progress in the young quarterback's development. But it also left Carlson's catch total stuck on zero after three games with his hometown team.

"Christian made the right play," Carlson said. "He shouldn't have thrown that ball."

Carlson has maintained a positive outlook despite his negligible impact. He's been targeted on only two passes in three games and played 65 snaps total, according to ProFootballFocus.

That's hardly the contribution the Vikings anticipated when they signed the veteran tight end and Litchfield native to a five-year, $25 million contract with $11 million guaranteed this past offseason.

The sample size is too small to make sweeping statements or assumptions, but two targets and no catches is at least a curious development for an offense that envisioned employing creative double-tight end sets with Carlson and Kyle Rudolph.

"The chips just haven't fallen in the right spot for him to receive the ball, but they will," Musgrave said. "He's going to get plenty of catches. It just hasn't happened yet."

Carlson doesn't blame anyone or project any frustration for his slow start. He's not pouting about it. He put in extra work after practices this week. He worked on his hand placement on the blocking sled and ran routes and caught passes from third-teamer McLeod Bethel-Thompson.

"I came in here to contribute to this offense and to help this team win," he said. "Offensively, we're doing great. Percy [Harvin] is playing out of this world. Kyle is having a big year already. Adrian [Peterson] and Toby [Gerhart] are doing great. Productivity-wise, obviously I'd like to contribute more. But I need to prove that I deserve a role in this offense."

That process usually happens in training camp, but Carlson suffered a sprained medial collateral ligament in his right knee in the second full-pads practice. He essentially missed all of camp, which put his timing and development with a new offense and new quarterback behind schedule. Carlson missed the 2011 season in Seattle because of a torn labrum in his left shoulder so his knee injury cost him valuable reps toward getting reacclimated to football.

"Absolutely there was rust, and there still is rust," he said. "But that's the way it is. I can't change that. The focus is to continue to improve."

Carlson's track record suggests he can be a viable target in the passing game when he's healthy and in the flow of the offense. He posted consecutive 50-catch seasons in Seattle and possesses the body type and athleticism that teams covet in pass-catching tight ends these days.

The Vikings need his presence in the passing game to provide some balance. Ponder has developed a connection and confidence with Rudolph and Harvin as his primary options. Those two have combined for 40 of Ponder's 68 completions.

Jerome Simpson joins the mix Sunday after serving his three-game suspension and should bring a vertical threat. Simpson's arrival presumably means fewer opportunities for others, but the Vikings are confident Carlson will carve out a meaningful role.

"We know what he can do," Ponder said. "We've seen him in practice, and he's practiced well and he's done well. We just have to continue to find ways to give him the ball. He'll come around."

Carlson doesn't sound concerned, either. He understands that Ponder has a certain trust level and rapport with Rudolph and Harvin. He believes his time will come soon, too.

"I know I can make plays in the passing game, but I have to earn that right to get my number called," he said. "When it is called, I need to step up and make plays."

Chip Scoggins • ascoggins@startribune.com