STILLWATER, Okla. — The two best days of spring rapidly approach.

Sunday, daylight-saving time starts giving sports enthusiasts an extra hour of sunlight to play games.

Monday, footballs will fill the air again as the Oklahoma State Cowboys restock after completing the best season in school history — a 12-1 record and Fiesta Bowl victory.

Oklahoma State coach Mike Gundy and his staff will have 15 practices to find replacements for the best quarterback — Brandon Weeden — and wide receiver — Justin Blackmon — in school history.

Quarterback is the biggest question mark.

The coaching staff wants one player to emerge as OSU’s starter during spring drills. They don’t want to start fall drills with a quarterback controversy on their hands.

The coaching staff will be evaluating three players.

Clint Chelf, a sophomore from Enid, has been Weeden’s understudy for two years. He has done something the other two haven’t — taken snaps under game conditions. Chelf has seen action in 10 games over two years. This past season he completed 20 of 30 passes for 307 yards and three touchdowns. He didn’t toss an interception.

J.W. Walsh, a redshirt freshman from Denton, Texas, will be going through his second round of spring practices. Walsh started attended classes at OSU in January 2011.

Wes Lunt, a true freshman from Rochester, Ill., enrolled in January and will get his first taste of spring drills.

The race for quarterback is wide open, Gundy said during his National Signing Day news conference on Feb. 1.

Chelf, Walsh and Lunt have just 15 practices to impress the coaches and follow in the footsteps of Weeden, Zac Robinson and Josh Fields.

The Pokes also must replace Blackmon, inside receiver Josh Cooper and senior receivers Colton Chelf and Hubert Anyiam.

It’s a daunting task, but the Cowboys used a lot of receivers this past season and should be able to reload fairly easily.

One receiver, Michael Harrison, won’t be a Cowboy next season. He has been suspended for a season by the NCAA and is leaving the program and university.

Isaiah Anderson, Tracy Moore, Charlie Moore and Josh Stewart should be able to step into starting and starring roles. The Cowboys have a half dozen or so returning receivers that will be evaluated this spring to earn a place on the depth chart.

Tight end Blake Jackson, a transfer from Scottsdale, Ariz., Community College, will be at spring drills as well. Jackson can either play inside receiver or tight end. He could make an immediate impact.

Defensive ends Jamie Blatnick and Richetti Jones completed their eligibility as did safety Markelle Martin.

OSU’s defensive staff will be looking for players to fill those gaps this spring.

Expect defensive tackle Nigel Nicholas to transition to one of the end positions during spring drills. Defensive end Cooper Bassett garnered a lot of playing time this past season and could be a starter as well. It will be harder to replace Martin who was a defensive leader.

The offensive and defensive coaching staffs will be looking for leaders to come to the forefront this spring.

In fact, finding leaders and building team chemistry will be just as important as replacing the winningest senior class in OSU history.