Buffalo Bills rookie starter Josh Allen has been diagnosed with

a sprained right elbow on his throwing arm and is not expected to play at Indianapolis this weekend Authentic Kyle Williams Jersey , a person with direct knowledge told The Associated Press on Tuesday.The person described Allen's status as being week to week as opposed to being out indefinitely. The person spoke to The AP on the condition of anonymity because the team has not revealed the nature of the injury.Coach Sean McDermott would only list Allen as week to week on Monday, and wouldn't rule him out from playing this weekend.The Bills (2-4) were off on Tuesday, and McDermott is next scheduled to address reporters once the team returns to practice Wednesday.Allen's injury, sustained in the third quarter of a 20-13 loss at Houston on Sunday, leaves Buffalo choosing between turnover-prone Nathan Peterman and newly signed veteran Derek Anderson to start against the Colts (1-5).Peterman has thrown four interceptions this season, including two in the final two minutes against Houston. The second-year player lost the starting job after faltering badly in a 47-3 season-opening loss at Baltimore.He's best remembered for throwing five interceptions in the first half of his first start in a 54-24 loss at the Los Angeles Chargers in November.Anderson is a 12-year veteran who was lured out of semiretirement to sign with Buffalo last week to mentor Allen. The 35-year-old Anderson attempted just eight passes in three appearances with Carolina last season, and hasn't started a game in nearly two years.Allen was drafted seventh overall out of Wyoming and has a 2-3 record.He was hurt while being struck from both sides by Whitney Mercilus and Jadeveon Clowney. Mercilus struck Allen's throwing arm just after the quarterback released the ball for a 39-yard completion to Kelvin Benjamin.Allen bent down and grabbed his arm in pain and stayed in for one more play — an incompletion to Zay Jones — before going down to one knee. He was then spotted yelling out in pain while trainers examined his elbow along the sideline.Buffalo Bills 20, LA Chargers 31: Bills shocked into submission The Buffalo Bills showed life late in the game, but dug a massive hole in the first half that couldn’t be overcome in a 31-20 loss to the Los Angeles Chargers. Rookie quarterback Josh Allen had an up and down day that included his first career touchdown http://www.buffalobillsteamonline.com/phillip-gaines-jersey , finishing 18 of 34 for 245 yards, a touchdown, and two interceptions. His west coast counterpart, Philip Rivers, was surgical with a 23-of-27 day for 256 yards and three touchdowns.Much like the Ravens in the season opener, the Chargers ran roughshod over the Bills in the first half. Philip Rivers had a nearly perfect passer rating and threw three touchdowns, while Austin Ekeler could not be tackled, and Los Angeles nearly ran up 300 yards in the first half. Buffalo’s offense looked better than week one, pretty much by default http://www.buffalobillsteamonline.com/stephen-hauschka-jersey , but they did score two field goals and turn a complete embarrassment into a typical NFL embarrassment.To their credit, the Bills settled down and looked like a respectable NFL team when the second half started. Josh Allen came out and engineered a touchdown drive (the first of the season) on the opening drive of the half, added a late passing touchdown, and the Bills defense held the Chargers to only three points in the second half. If a few more key plays had broken their way, the team could’ve engineered a full comeback. Two forced fumbles were blown dead, and a tipped pass fell into the hands of a Chargers receiver instead of a Bills defender. Josh Allen took a couple risks trying to close the gap, and they turned into a pair of drive-killing interceptions. The Bills will lick their wounds and try to carry some of the positive feelings from the second half into Minnesota next week when they play the Vikings.TakeawaysAllen looked like he could handle the NFL spotlight for most of the game, but still made a handful of rookie mistakes. He misread the defensive front on several plays, which contributed to LA’s five sacks.Tremaine Edmunds took a step back from his great performance in week one. While he tied for the team lead with seven tackles Youth LeSean McCoy Jersey , the Chargers constantly picked on him in coverage. He missed some tackles against speedier receivers and runners.To make one excuse for Edmunds, injuries and Buffalo’s roster configuration put him in an uncomfortable position, like man coverage against slot receiver Keenan Allen.Zay Jones nearly dropped it, but hauled in a 57-yard pass from Josh Allen in the first half.Chris Ivory made a goalline appearance to score a rushing touchdown at the start of the second half.The Bills pass rush came to life, and Jerry Hughes and Lorenzo Alexander recorded sacks today.Injury notesPhillip Gaines injured his shoulder in the first quarter of the game. He was replaced by Rafael Bush and with the Bills running more base defense personnel.Taiwan Jones suffered a head laceration when he tried recovering a muffed punt, lost his helmet, and took a hit to the face from a Chargers defender.LeSean McCoy injured his ribs when Ryan Groy fell on top of him on a run. He made a brief appearance in the game but sat out the rest of the day.Rafael Bush was also injured late in the fourth quarter, and was helped off the field.