The San Diego Chargers needed to get away after a difficult loss, yet they couldn't escape controversy during their bye week.

Still awaiting the results of a league probe regarding the possible use of an illegal substance in their last game, the Chargers will try to avoid a third straight loss Sunday when they visit a Cleveland Browns team which could be missing Trent Richardson.

Instead of heading into the bye with a two-game lead atop the AFC West, the Chargers (3-3) went into their break tied with Denver after giving up 35 unanswered second-half points in a 35-24 loss to the Broncos on Oct. 15.

It tied for the fourth-biggest regular-season comeback in NFL history, and came just a week after San Diego surrendered the final 17 points in a 31-24 loss to previously winless New Orleans.

"When you lose it's rough, especially in a game where you had a big lead and so much at stake," said Philip Rivers, who had career highs with four interceptions and six turnovers against Denver.

If losing a double-digit lead for a second consecutive week wasn't bad enough -- or team spokesman Bill Johnston telling fans to "take a chill pill" in a column on the team's website -- San Diego is now being investigated for using a banned substance against Denver. Fox Sports first reported that a Chargers equipment manager came on to the field with an illegal substance on hand towels.

The report also said the equipment manager refused to hand over the towels to a line judge, and that skin-colored or a clear type of tape was found after officials made him empty his pockets.

Chargers coach Norv Turner claims the NFL investigation is about the hand towels, not an illegal substance.

"Nobody in this organization has used Stickum in any game," Turner said Monday of the product that was banned by the league in 1981. "The question involved a towel that has been used by this organization for over 10 years. It's used by a lot of teams in this league. The towel is used to dry the balls, dry the gloves that the players wear and their arms. The league is looking into the towel. That's about where it's at."

On the field, the Chargers are expected to use a more cautious approach on offense as turnovers -- 13 in the last four games -- are becoming a major concern. Shorter routes could benefit Rivers, who has been sacked 12 times in the last three games and is 2 for 12 with three INTs this season on throws 31 yards and longer.

The Browns defense, meanwhile, tops the AFC with 10 interceptions and is among the conference leaders with 18 sacks.

The offense also has shown some positive signs behind rookie quarterback Brandon Weeden, as Cleveland (1-6) had no turnovers for the first time this season in last Sunday's 17-13 loss at Indianapolis.

However, the Browns could be without Richardson, the team leader with 348 yards and 24 receptions, due to a rib cartilage injury.

The rookie running back was pulled last Sunday after rushing for eight yards on eight carries.

"If he's ready to play, he'll play," coach Pat Shurmur said. "If we see that this is bothering him to the point where he can't perform, then we'll make those decisions as we go."

If Richardson can't go, Montario Hardesty and Chris Ogbonnaya are expected to get the bulk of the carries.

Given the Chargers' league-best rush defense (71.2 ypg), Weeden might get more opportunities to spread the ball around. He connected with nine receivers last Sunday, with Greg Little and Josh Gordon each catching touchdowns.

The Browns' line has done a great job protecting Weeden, allowing three sacks over the past four games, but that unit has lost starting left guard Jason Pinkston for the season due to life-threatening blood clots in his lungs. Pinkston was released from the Cleveland Clinic on Wednesday, two days after being placed on injured reserve.

John Greco will likely replace Pinkston. Greco started last Sunday when Cleveland rushed for 55 yards.

"I thought John stepped in and did okay," Shurmur told the Browns' official website. "Anytime you remove a piece though, there's a little bit of getting used to."

San Diego is used to defeating Cleveland, winning the last four meetings and nine of 11.

The last time these teams met, the Chargers won 30-23 in Cleveland on Dec, 23, 2009. Rivers threw for 373 yards and two TDs while tight end Antonio Gates caught eight passes for a career-best 167 yards.

Gates had a season-high 81 yards against Denver with two touchdowns after having none through his first four games.