Denver Post beat writer Ryan O'Halloran answered a question about Drew Lock:
The Broncos, of course, want Drew Lock to succeed and the current situation — chiefly, the leaky pass protection — may be giving John Elway, Vic Fangio and Co., pause about when to start Lock. I would start Brandon Allen against the Chargers and then hand the keys to Lock for the final four games.
Obviously this is just the writer's plan, but he feels letting Lock take in a game as a backup first would be better than throwing him in a game when activated - especially with a lost season already.
DEN QB Brandon Allen - Week 13 Fantasy Football Outlook
Week 13 vs. Los Angeles Chargers
Brandon Allen and the Broncos offense had all sorts of trouble in Buffalo last week, generating just 134 total yards and three points. Against a good defense, Allen completed only 10 passes for 82 yards and rushed for eight yards. The QB and his mobility helped light a spark for Denver in his first two starts, something the team will need at home versus the Chargers No. 4 pass defense. Joe Flacco threw for less than 200 yards with a TD in the Week 5 win at Los Angeles, but Allen should only be in your starting lineup if you’re desperate.