GLENDALE, Ariz. -- Cleveland's Colt McCoy and Arizona's Kevin Kolb will miss Sunday's matchup between the Browns and the Cardinals after leaving their previous games with concussions.
McCoy's return to the game after the nasty hit he took in a 14-3 loss to Pittsburgh dominated the conversation in Cleveland all week. He did not travel with the team to Arizona and Seneca Wallace will start in his place Sunday.
The situation was quieter in Arizona, where Kolb took a knee to the head on the third play of the Cardinals' 21-19 win over San Francisco. He was removed from the game immediately, and after evaluation, did not return.
Kolb practiced all week, increasing his participation each day. John Skelton was named the starter Saturday, but Kolb has not be ruled out of the contest.
In Cleveland, Wallace knows the Cardinals from his days playing for division rival Seattle.
"I was in that division for a long time," he said. "Obviously some of their players have changed over the last few years, but they have some of their key components of guys from when I was there so it kind of feels like I'm going back home again in that division."
It's a far different Arizona defense than Wallace remembers, though.
The Cardinals (6-7) have won three in a row and five of six after a six-game losing streak. A victory over Cleveland would put them at .500 for the first time since the second week of the season. The team even still has a longshot at the playoffs, and a victory would make Ken Whisenhunt the winningest coach in franchise history with 43.
A big reason for this season's turnaround is the improving defense of first-year coordinator Ray Horton. Arizona has given up six touchdowns in those past six games.
"I think it's just playing as a team and building our confidence that we actually can win," defensive end Calais Campbell said, "and then just being more comfortable with the scheme."
The Cardinals had five sacks -- from five different players -- in each of their two most recent wins, against division leaders Dallas and San Francisco.
"I would rather have five guys have five sacks than have one guy have five sacks," Whisenhunt said, "because it makes you much more difficult to defend when you do that."
Horton came from Pittsburgh and his scheme is based on that of the Steelers, a team Cleveland plays twice a season.
"If you're going to have a defense that you want to be similar to, it's hard to beat that," Browns coach Pat Shurmur said. "With the history of Horton, they are very similar. We see a lot of the same elements of the defense that we just played against Thursday. They're playing it pretty well."
Because they are coming off a Thursday night game, the Browns (4-9) have had some extra time to use their recent experience with the Steelers to prepare for a cross-country journey to meet the Cardinals for the first time since 2007.
"It's similar, so some of the things that we thought might have been effective last week, we feel like will give us a chance," Shurmur said. "But you have some different pieces in place. How they play the coverage is a little bit different, so that affects some of the things you might do throwing the football."
While Arizona has rebounded from its early season funk, the Browns have lost three straight, six of seven and eight of 10. Their offense has been the biggest problem, scoring 20 or more points just twice this season. They have lost by a combined 38-13 to AFC powers Baltimore and Pittsburgh the past two games.
The Cardinals are unaccustomed to the favorite's role, leaving the possibility of a letdown. Arizona's Larry Fitzgerald, who caught seven passes for 149 yards last week against the 49ers, said Cleveland's record is deceiving.
"They have one of the best defenses in the league, especially against the pass, so we're going to have a struggle with this group," he said. "We know the kind of competition they play. They play the Ravens two times a year, they play the Steelers two times a year, they play a good Bengals team two times a year. They play in the AFC North, one of the toughest divisions in football."
Cleveland ranks second in the NFL in pass defense (180.7 yards per game) but 31st in run defense (150.9 per game).
That could mean a game plan geared toward Beanie Wells. Wells' statistics were down against Dallas and San Francisco after his franchise-record 228-yard romp against St. Louis.
Arizona is hoping to overcome its habit of starting slowly on offense.
The Cardinals trailed at halftime of all five of their recent victories -- by a combined score of 51-19 -- but in the second half (and overtime in two of the wins) they outscored their opponents 81-27.