MORE: Three burning questions facing the Purdue defense this spring | Three burning questions facing the Purdue offense this spring | Spring football schedule

Spring is the time for player development. And--with no games to prep for--there is plenty of time for individual instruction during the 15 allotted practices set to begin on Friday for Purdue.

While it's important for everyone to improve, here are some key players to watch especially close this spring.

Note: Players listed alphabetically.