The defense is an issue for Bolton Wanderers and has been for quite some time (shocker, I know). Since the start of Owen Coyle's Bolton tenure with the 0-2 loss to Arsenal at home during the 2009 / 2010 season, Bolton Wanderers have kept only six clean sheets. That's 104 league matches and six clean sheets, or in other words, one clean sheet every 17.33 games. If you had to guess which Bolton man partnered with Zat Knight at centerback and you said "Gary Cahill," you would be wrong.
In early February of 2010, at the tail end of the 2009 / 2010 season, Bolton Wanderers were locked in a desperate fight to stay up. The Trotters were in 16th place in a four-place deadlock on 21 points with West Ham United, Wolverhampton Wanderers, and Hull City. Goal differential was keeping them two spots clear of the drop zone. Wanderers had just received the devastating news that Gary Cahill would miss a large portion of the season with a blood clot in his arm, one that would require a heavy dose of blood-thinning medication. The options for central defense were few and far between past Cahill with Andy O'Brien the only true central defender of the bunch.
O'Brien was never going to be the first choice, making only six appearances that entire season. It was the versatile Samuel Ricketts that stepped into the vacant role to help Zat Knight keep the ball away from goal. In Cahill's absence, Ricketts played eight Premier League games at center back from early February to early March. That run of matches included Fulham, Manchester City, Tottenham, Wigan, Blackburn, Wolverhampton Wanderers, West Ham United, and Sunderland. Ricketts demonstrated that he was up for the task and then some.
In those eight matches, Bolton Wanderers allowed a total of 11 goals or an average of 1.375 goals per game. Toput that into perspective, Bolton allowed a total of 67 goals that season, 1.76 per game. Over the course of the season, Bolton were much more likely to allow two goals per game than the one when Ricketts was at the center of defense. In that stretch of eight games, Bolton kept clean sheets on three occasions with 0-0 draws against Fulham and Wigan and a 1-0 win against Wolves.
So far this season, Bolton have allowed 12 goals from eight matches and are facing teams fairly far from the caliber of those in the Premier League. As for Sam Ricketts, he's made four appearances in the Championship so far: one win, one draw, and two losses. Stephen Warnock will have the left back position as his while he's at Bolton and Tyrone Mears looks to be Coyle's favorite on the right. Matt Mills and Zat Knight are forming a partnership in the center as we speak but should that not go to plan, Bolton have more than a reliable option to help at the centerback position.
h/t to Chris Manning for bringing up the original point