He seemed to be healthy enough in the playoff game against San Diego last season, but was uncharacteristically erratic and lost a fumble after a fairly innocuous hit.
For the Colts to be comfortable moving forward with Harrison this season, he needs to show them early and often that he is mentally and physically in game condition.
2. Josh Thomas: Thomas and fellow reserve end Jeff Charleston had mediocre performances against the Redskins in the Hall of Fame game, so they both will be under the microscope given the surprisingly good play of rookies Marcus Howard and Curtis Johnson.
The Colts generally keep four ends, but may keep five with this group.
Out of everyone vying for a job, Thomas has the highest salary cap number and hasn't done much to distinguish himself. With Dwight Freeney watching from the sidelines, he will get that opportunity. Will he make the most of it, or will he continue to languish?
Kenton Keith needs to show he deserves to hang onto his roster spot
AP Photo/Michael Conroy
3. Kenton Keith: His off-field issues in the offseason and Mike Hart emerging as a player to watch this preseason has only intensified the pressure on Keith. He's still the third-most experienced back currently in camp and came through for the Colts when they needed him to fill in for Joseph Addai in 2007.
But, in the what-have-you-done-for-me-lately culture of the NFL, you're only as good as your last performance. Since the defining moment of Keith's last two games are a dropped pass that led to an interception in a playoff game and three rushes for ten yards against the Redskins, he certainly needs to have a strong performance on Saturday to gain some traction.
With five preseason games to work with, Tony Dungy will probably limit Addai's workload in the next two games. The first test for Keith comes on Saturday. Will he pass?
4. Jordan Senn: With the rash of injuries that has befallen the linebacking corps, Senn has a rare opportunity to seize a roster spot and hope to hang on once everyone has recovered from their ailments. As mentioned in my rookie review of the Hall of Fame game, Senn was all over the field against Washington, recording 11 tackles, but was also all over the place, looking flat-footed and struggling some in coverage.
Currently, there are five linebackers on the roster that are well enough to practice and four of them, including Senn are undrafted — Freddy Keiaho is the only member of the squad to be selected and he's not fighting for a job.
What that means, though, is that Senn has as good a chance as anyone to leave a favorable impression on the Indianapolis staff.
He has already shown a knack for being around the ball, so what he needs to improve upon is being around the ball in the proper position according the system.
The Colts coaches know as well as anyone that when the plays start counting during the regular season, being where you're supposed to be is more important than whether or not you chase down the ball carrier after they've sprinted past you and getting a nod from the statistician.
The firmer his grasp on the defense and the more in control he appears during the course of the play, the better for Senn.
5. Gijon Robinson: After the Colts drafted two tight ends in April, Robinson must have wondered if his time on the Indianapolis practice squad was an exercise in futility.
However, they also let Ben Utecht and Bryan Fletcher walk during free agency, which certainly must have bolstered his spirits. And, with Tom Santi still shelved with a bursa sac issue and Jacob Tamme failing to establish himself as the top back-up, Robinson has a real shot to build on the momentum he has so far with another good outing.
If he can come out with another strong performance, the competition at the number two tight end spot may be over. It's up to Robinson to make that happen.