ORCHARD PARK, N.Y. -- The Buffalo Bills will wrap up more than two months of offseason workouts and practices with a three-day mandatory minicamp that begins Tuesday.

The practices, which are closed to the public and can't be held in pads, are the final tune-up before players depart for a six-week break leading into training camp.

Here is what we'll be watching:

1. Does Chris Williams participate? Veteran guard Chris Williams was the only player not to report for voluntary offseason workouts or organized team activities. General manager Doug Whaley told The Associated Press last week that Williams missed time because of his back surgery (a procedure that Rex Ryan noted in April), but Whaley's comments don't explain why Williams hasn't been rehabbing at the Bills' facility like other players who underwent offseason surgeries, or why Ryan has said he hasn't been in contact with Williams this offseason. Williams must report for this week's minicamp -- or he risks being fined -- and if he does, he might not participate in practices because of his rehab. Rookie John Miller has the inside track over Williams to start at guard.

2. Do injured players ramp up participation? Wide receiver Sammy Watkins, cornerbacks Leodis McKelvin and Stephon Gilmore, and safety Aaron Williams have all been held out of full-team drills this offseason because of offseason surgeries. This week will be their final chance to take part in those drills before training camp. It's not a big deal either way -- this three-day stretch won't make or break their seasons, and it might make more sense to hold those four players out until July -- but it's still something worth watching as training camp draws nearer.

3. How do quarterbacks perform? Unlike OTAs, where reporters were limited to watching one out of every three practices, the NFL mandates that all three minicamp sessions be fully open to reporters. That will allow us a consistent look over the week at the quarterback competition. Matt Cassel struggled in the final OTA open to reporters last Wednesday, while Tyrod Taylor was working with the second and third teams. If those trends continue this week, expect EJ Manuel to be discussed over the next month as the favorite to win the starting job entering training camp. If Cassel rebounds and Taylor gets more time with the top unit, it's anyone's race.

4. Can Cyrus Kouandjio keep up momentum? Seeing Kouandjio line up at first-team right tackle for the majority of OTAs was a surprise. If he keeps that spot through this week -- and Seantrel Henderson remains at second-team left tackle -- it will support the theory that Kouandjio is making material progress, and his snaps with the first team are more than just an experiment by new offensive line Aaron Kromer.