Detroit’s record isn’t very good through six games, but Matthew Stafford’s numbers are very similar to last season at this stage. (US Presswire)

Through six games of the 2011 season, Detroit was 5-1. The Lions were in the thick of the NFC North title race, and the tandem of Matthew Stafford and Calvin Johnson was emerging as one of the NFL’s top quarterback-receiver partnerships.

A year later, Detroit is 2-4, facing a must-win game Sunday to remain a realistic contender for a playoff berth, and the Lions’ offense is a shadow of its former self.

Popular opinion among Lions fans and NFL experts alike is that a large part of the blame for Detroit’s offensive struggles fall on a seemingly slumping Stafford, but Lions coaches and Stafford himself maintain there’s been no change in the way he plays the game.

“I wouldn’t say [Stafford’s] regressed,” coach Jim Schwartz said. “I think as an offense we’re working through some things right now. We’re not clicking on all cylinders. We have the firepower to do it and Matt’s certainly capable.”

At first glance, Schwartz’s comments seem like PR spin from a coach struggling to find answers for a lack of performance.

A glance at the stat sheet, however, gives Schwartz’s claims some credence.

As it turns out, Stafford’s numbers this season are comparable to or above his stats through six games last year in almost every category. He has 1,754 passing yards in 2012 compared with 1,729 last year, has completed 17 more passes (164 this year compared to 147 last season), has an identical completion percentage (62 percent) and is within a yard on his average yards per completion.

In short: Stafford’s production hasn’t waned from his breakout performance last year.

But there's one exception. Stafford has just five TD passes this year, compared to 15 last season, and he has found the end zone only once in the first half all year. It’s worth noting, though, that he hasn’t gotten much help from his receivers. Titus Young and Brandon Pettigrew have dropped passes in key situations, and Johnson has yet to make a touchdown catch.

Stafford’s explanation is simple: After throwing for more than 5,000 yards last year, he and his teammates are getting more respect.

“We’ve seen less blitzes than last year,” he said. “That’s kind of a sign of respect that teams are not willing to blitz you because they know you have a good plan against it.”

Still, Stafford admits the offense must get across the goal line more often, and he says the Lions have to find a way to make opponents pay for the extra defensive attention Johnson has gotten.

“A lot of teams have done a good job of keeping [Johnson] out of the end zone,” he said. “When we get inside the 10-yard line, they’re clamping him, sending safeties over, and we’ve just got to hurt them in other ways. Other guys are just going to have to step up and make plays, including myself.”

Despite Detroit’s subpar record and questions about his performance, Stafford isn’t lacking in the one intangible found in winning quarterbacks that can’t be coached: confidence. He says the challenges he’s faced in his four-year career have given him the necessary tools to get the offense back on track, and he won’t let his critics impact his performance.

“My first three years in the league prepared me for moments that are tough,” he said. “Obviously, we’re not playing as well as we can on offense, but the one thing I’m not going to do is freak out or panic.”

Lions sign WR Robiskie to replace injured Burleson: Detroit signed former Browns and Jaguars receiver Brian Robiskie to replace Nate Burleson, who was placed on injured reserve after breaking his leg Monday against the Bears. Robiskie was a second-round draft pick of the Browns in 2009, and he had 39 receptions for 441 yards and three touchdowns in three seasons in Cleveland. He was released by the Jaguars earlier this month. Signing Robiskie gives the Lions a full complement of receivers, but it’s likely that he’ll be at the bottom of the depth chart behind Titus Young and Ryan Broyles.

Injury report: The Lions held a walk-through practice Wednesday. The non-contact workout was closed to media, and the Lions released a practice report that was based on estimations of what would have taken place in a contact workout. Estimated non-participation -- DE Cliff Avril (back), WR Calvin Johnson (knee), CB Jacob Lacey (concussion), LB DeAndre Levy (hamstring), DE Ronnell Lewis (not injury related), and S Amari Spievey (concussion). Estimated limited participation --  CB Bill Bentley (shoulder), S Louis Delmas (knee), TE Brandon Pettigrew (knee), LB Stephen Tulloch (knee), DT Corey Williams (knee), and WR Titus Young (knee).

Follow Lions reporter John Kreger on Twitter at @CBSLions and @JohnKreger.