BOISE — The Boise State football team will hold the first of 15 spring practices Friday at 7 a.m. inside the Caven-Williams Sports Complex.

The Broncos, coming off a 10-3 season and an appearance in the Mountain West championship game, have several holes to fill heading into the 2019 season including at quarterback, running back and wide receiver. Boise State also will have three new coaches on defense and impact players to replace there, as well as new specialists at both kicker and punter.

The annual Spring Game is set for April 6 at 3:30 p.m.

Here are five things to watch for over the next month as the Broncos get back on the practice field:

QUARTERBACK BATTLE: It’s no secret that replacing Brett Rypien is the biggest offseason storyline for the Broncos. The record-setter will be on the field at the NFL Scouting Combine in Indianapolis, Indiana, on Friday morning when the Broncos take their first step toward trying to replace him. Projected starter Chase Cord suffered a torn ACL during practice last year, which will keep him out until fall camp at the earliest. That means all eyes will be on a pair of true freshmen that enrolled early in Hank Bachmeier and Kaiden Bennett. Both put up monster numbers in high school and come in with plenty of hype as they try to win the job in their first year on campus. Returners Jaylon Henderson and Riley Smith also will compete for the spot during spring practices. Cord will likely get a shot to win the job if he’s healthy during fall camp, but which other quarterback positions himself best during the spring to challenge in the fall will be the most fascinating to keep tabs on.

REPLACING MATTISON: If losing Rypien is Boise State’s biggest individual loss from last season, the departure of Alexander Mattison is not far behind. Mattison is at the NFL Scouting Combine this week with Rypien as he looks to improve his draft stock, leaving the Broncos with a huge hole to fill in the backfield. Andrew Van Buren came in highly-touted as a true freshman last year and rushed for 163 yards on 34 attempts as the backup. He’ll get the first crack to take over as the featured back, but the Broncos have plenty of quality depth at running back that should make for a fun competition.

Danny Smith redshirted last season and will get plenty of reps this spring, while two big-time recruits, Keegan Duncan and George Holani, will enter the mix when they arrive this summer. Robert Mahone has yet to show his full potential, but he’ll get an opportunity to show what he can do this spring. Is Van Buren ready to be the next great Boise State running back? Will either Smith or Mahone emerge this spring? Keep an eye on the running backs this spring.

IMPACT PLAYERS LOST ON DEFENSE: Boise State must replace three of its top six tacklers from last season including one at every level of the defense. Second-leading tackler Tyson Maeva was booted from the team after an incident at the bowl game in Dallas, while corner Tyler Horton and STUD Jabril Frazier both graduated. Horton, Frazier and defensive end Durrant Miles all figure to get a look by NFL teams in the coming months and leave the Broncos with key holes to fill. Horton was a two-time first-team All-Mountain West selection and had three defensive touchdowns last season. Jalen Walker was listed as the backup on the depth chart to finish last season and could be in line to take over as the starter.

Frazier was second on the team with 5.5 sacks and 9.0 tackles-for-loss and also was a first-team selection. Curtis Weaver returns to anchor the STUD position, but who will step up to replace Frazier? Maeva was only a junior and expected to lead the defense next season before he was kicked off the team, leaving the Broncos with an unexpected spot to replace. Benton Wickersham will get a shot to replace him, as will a few newcomers. The Broncos bring back seven starters on defense, but the ones they lose were impact players. Developing depth this spring will be key.

SPECIAL TEAMS CHANGES: The special teams units will be worth watching this spring due to the departures of kicker Haden Hoggarth and punter Quinn Skillin. The Broncos also removed Kent Riddle from his duties as special teams coach and named Lee Marks and newcomer Jeff Schmidding as co-special teams coaches. The Broncos had their worst statistical years in both field goal kicking and punting in more than a decade and struggled across the board on special teams. Riddle went as far as to say the units cost the Broncos a championship after an extra point was blocked in the fourth quarter of the Mountain West title game that would have given the Broncos the lead. Boise State also had two punts blocked last year in the loss at Oklahoma State.

Joel Velazquez returns and will likely handle both the punting and field goal duties during spring practices, but has been inconsistent when given a chance in the past. The Broncos gave a scholarship to prep punter Gavin Wale and also will add Division III Trinity College transfer kicker Eric Sachse to the mix. It’s unclear if Sachse is already on campus and will participate in spring practices. He made 29 of 36 career field goals at Trinity. Wale will arrive this summer.

NO DEFENSIVE COORDINATOR: Boise State will open practice Friday without a defensive coordinator after Andy Avalos left earlier this week for the same job at Oregon. Losing maybe the most talented coach on the staff would be a big deal no matter what, but doing so three days before the start of spring practice leaves the Broncos in a big hole. Boise State already was going to be breaking in two new coaches on defense this spring in corners coach Jalil Brown and outside linebackers coach Jeff Schmidding, but now will practice Friday with just two coaches on defense that were here last season. And only one, safeties coach Gabe Franklin, is in the same role he had in 2018. Spencer Danielson moved from coaching the STUDs last season to the defensive line.

Who coordinates the defense this spring and how they operate with the departures of three of the five coaches from last season will be interesting to follow. Also worth paying attention to is how quickly coach Bryan Harsin hires a new defensive coordinator and who that person will be. Avalos has been with the Broncos since 2012 and spent the past three years as the defensive coordinator. The defense was a strength of the team under Avalos, and what the group looks like without him moving forward is a big question mark.

The Idaho Press and BlueTurfSports.com will have complete coverage of Boise State’s spring practices all month with stories, photos, video interviews and more. Check BlueTurfSports.com and read the Idaho Press daily to stay up to date on what’s happening with the Broncos as they inch closer to the 2019 season opener on August. 31 against Florida State in Jacksonville, Florida.