Siemian was sacked five times and committed two turnovers in Denver's 21-0 loss to the Chargers last week that marked the franchise's first shutout since Nov. 22, 1992, when the 25-year-old quarterback was still in diapers.
It also extended a month-long funk for the Broncos (3-3), who have lost three of four heading into a brutal three-week stretch in which they'll face the Chiefs (5-2), Eagles (6-1) and Patriots (5-2), three of the top four teams in this week's AP Pro32 poll .
"It's tough to get on guys when you're not playing well," Siemian said. "I have to play better.