Shane Matthews is Buffalo's No. 3 quarterback.
Holcomb does appear ready to resume taking snaps as Buffalo's starter, but Mularkey, just as he did a week ago, is putting off making a decision on who gets the nod for this week's home game against Carolina.
Despite their 48-10 loss to the Chargers, the Bills (4-6) are still only two games out of first place in the AFC East behind New England (6-4) with six games to play. Nobody is assuming Losman won the job back with his gutsy performance against San Diego, when he threw for 168 yards with one touchdown and one interception and was sacked six times.
As long as Buffalo remains mathematically alive for a playoff berth, it's expected that Mularkey will play musical chairs with his quarterbacks, starting the one he feels gives him the best chance to win in any given week.
He liked that Losman got some valuable experience and played a full game against the Chargers, his first start in more than a month. But making the playoffs, not developing a young quarterback, is still Mularkey's priority.
"I don't know, that's his call," said Losman when asked if Mularkey has any justification to go back to Holcomb at this point. "I have no control over that. If they want me to play, I'm going to play. No matter what, I'm going to scratch and fight to get in there."
--QB Kelly Holcomb, who had started five games in a row, dressed as the No. 2 quarterback at San Diego following a severe concussion. He's close to being fully recovered but it still has not been determined if he'll get the starting job back for this week's game against Carolina at home.
--QB J.P. Losman's record as a starter fell to 1-4 with Sunday's 48-10 loss at San Diego. He threw the ball much better and his decisions were quicker, but it still has not been determined if he'll start this week's home game against Carolina.
--RB Willis McGahee has had costly fumbles in each of his last two games. He's playing with bruised fingers on one hand. McGahee is in a mini-slump, having been held to under 100 yards in three of his last four games.
--RB Shaud Williams remains the team's top backup with 31 carries for 116 yards. He had only one carry last week at San Diego, that for a 4-yard loss when he was met in the backfield by a defender after a badly missed block up front.
--WR Lee Evans caught a 42-yard pass late in the game at San Diego, giving him his ninth career catch of 40 yards or longer in less than two seasons. It was his third such catch this season.
--WR Eric Moulds needs just three receptions to post his eight career 50-catch season. Only Andre Reed (13) has more 50-catch seasons in team history.
--WR Josh Reed has a catch in all 10 games but lost whatever credibility he had built up with two dropped balls in the loss at San Diego. Reed continues to be plagued by lapses in concentration, something the coaching staff hoped he licked coming out of training camp.
--TE Tim Euhus caught his first two passes of the season at San Diego and his first since last December when he underwent ACL surgery.
--CB/KR Terrence McGee, the NFL's leading kickoff return man, has been limited to one return in each of his last two games. He re-aggravated a sore hamstring against the Chargers and played sparingly after that. His status is questionable for Sunday at home against Carolina.
--PK Rian Lindell, who boomed a 53-yard field goal last week at San Diego, his longest as a Bill, is 18 of 22 for the season. For his Buffalo career, he's 59 of 74 for a team-record 79.73 percentage. Steve Christie is second at 78.26.
--DT Sam Adams is now battling a bad knee and a bad ankle. He left the Chargers game in the second quarter after his ankle was rolled on and did not return. It's likely his practice time will be limited this week but he will be ready for Carolina on Sunday.
--LB Jeff Posey had a sack and forced fumble against the Chargers, his first sack of the season. Posey was signed as a free agent in 2003 after an eight-sack season for Houston but hasn't been given the chance to rush the passer on a regular basis in Buffalo's scheme where he often is used in coverage. Posey has 18.5 sacks in his career, but just two the past two seasons. Sunday's game may earn him more opportunities for sacks.