San Diego Chargers wide receiver Keenan Allen had to leave practice to get treatment on his knee on Tuesday. Allen was sent to the athletic trainer's room, and it's unclear if it's specifically related to his PCL injury from college. Losing Allen for any amount of time would be a blow for the Chargers, who lost Danario Alexander to an ACL injury and have Malcom Floyd banged up with a knee sprain as well.
Here's what else you might have missed from Tuesday:
Cleveland Browns running back Trent Richardson is recovering from a shin injury and a muscle strain, and is on track to make his preseason debut this week. Richardson sat out the entire preseason due to injury last season, and missed the first preseason game this year. He's supposed to be Cleveland's feature back, and given that he's only in his second year, the Browns definitely want to get him as many reps as they can.
Both the NFL and the NFL Players Association have agreed to conduct HGH testing, and they're getting closer to figuring out the framework of how the population testing will work. The two sides have tentatively agreed to the structure of the testing and how those tests will be handled over the course of a season.
Tennessee Titans wide receivers Kenny Britt and Kendall Wright both missed practice on Tuesday. Britt missed his third straight day due to swelling and soreness in his right knee, while Wright was out due to a sore calf. The injuries both appear minor, but they are definitely a concern given that these are Tennessee's top receivers.
Washington Redskins rookie safety Phillip Thomas will miss the 2013 season due to a Lisfranc injury. Thomas is expected to miss 4-5 months, and he'll have surgery before being placed on injured reserve. He was a fourth-round draft pick this year and was set to provide depth on defense and possibly start in the future, but this is a major setback for his career.