During the Arizona Cardinals’ four-game winning streak, the offensive line did a relatively nice job of protecting quarterback Carson Palmer, allowing just 10 sacks over that span.

Pass protection wasn’t the Cardinals’ strong suit Sunday, though, as they allowed five sacks in a 24-21 loss to the Philadelphia Eagles. Left tackle Bradley Sowell was responsible for two of them.

Cardinals general manager Steve Keim knows that the team’s offensive line, specifically the left tackle position, is very much a work in progress.

“We started off this spring knowing we had to address it and went out and signed Eric Winston in free agency, and he’s done a nice job for us,” Keim told Doug and Wolf Monday on Arizona Sports 620. “Obviously drafted Jonathan Cooper high, we were counting on him and lost him in training camp, which was a huge blow.

“The left tackle, you can’t create them. It’s tough, you have to do your due diligence and look in free agency and look in the draft and if the player doesn’t fall to you, you can’t force it. We’ll continue to try to add more depth and try to see if we can grow in that position.”

Sowell, a second-year player out of Mississippi, wasn’t with the team in training camp. The Cardinals acquired him off waivers when he was released by the Indianapolis Colts. He became the full-time starter at left tackle in Week 5 against Carolina after the team traded Levi Brown to the Pittsburgh Steelers, and has struggled for the most part.

ProFootballFocus.com has Sowell ranked 76th out of 77 NFL tackles with an overall grade of -27.7. Only Jordan Mills of the Chicago Bears (-33.5) ranks lower.

“It’s tough, left tackle is one of the hardest positions to find aside from quarterback and pass rushers,” Keim said. “It’s always going to be a challenge and that’s why those guys aren’t hanging around in free agency.”

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