By Matt Audilet Keenan Allen is expected to miss his fifth game in a row after suffering a hamstring injury in Week 1. The Los Angeles Chargers wide receiver says he “doubts” he’ll be able to take the field for Monday night’s primetime matchup against the Denver Broncos. That being said, Allen has high hopes for a return to the field for Week 7’s matchup against the Seattle Seahawks. “Last week was definitely when I wanted to get back, but that didn’t happen,” Allen said, per ESPN. “We’re just playing it day-by-day. This week would be great, but I don’t think I’m going to make it. So, Seattle’…