Calais Campbell should be signed long-term to the Arizona Cardinals. He probably was the most dominating player on the team's defense this past season. That doesn't mean he has an awesome game every time he plays. Early in the season, he had one of his most impressive games of the season against the Seattle Seahawks, logging 2.5 sacks and 10 tackles, five of which were solo tackles.
In Week 17 against the same team, he did not do so well. In fact, hemade the Pro Football Focus "Had a Bad Day" list.
In the final game of the season, he logged one solo tackle...and that was it. Granted, he did not play as much. He only played 41 snaps (just over half), when on the season he played over 87 percent of the snaps. Seattle probably game planned a bit for him.
The result? A -3.2 grade for him. According to PFF's game log, he missed a pair of tackles. In the article it speculates that he must have been hurt. He was not on the injury report at all that week, so if he was hurt, it was nothing serious. However, coach Ken Whisenhunt and DC Ray Horton subbed him out much more quickly than normal, as the game was technically meaningless.
On the bright side, Vonnie Holliday, who got more snaps than normal, played a great game to balance out Campbell's play, so in the end it was still a Cardinals victory.
In the end, while the grade and negative notoriety for one week might not be great, it is certainly nothing to really worry about.