Thursday’s announcement that Clemson quarterback Trevor Lawrence, a leading Heisman Trophy candidate, has tested positive for COVID-19 sent a jolt through college football as it prepares for a Halloween weekend of double-digit favorites among the nation’s top-five teams.

Here is a look at some games to watch:

Boston College at No. 1 Clemson, noon, 6ABC

Lawrence, who has thrown 17 touchdown passes this season, issued a statement Thursday night on Twitter saying he is experiencing “relatively mild” symptoms. He added: “The only thing that hurts is missing an opportunity to be with my teammates this weekend and play the game I love.”

Now the countdown is underway to determine whether Lawrence will be eligible to play next Saturday in the big game at Notre Dame. His positive test came on Wednesday and the ACC protocol of 10 days in isolation will expire that day, Nov. 7, but he also must undergo a cardiac evaluation that could add to the 10 days.

True freshman D.J. Uiagalelei is expected to get the call at quarterback against BC. While that might lower the point spread, the Tigers still are expected to achieve a 7-0 start for the third straight season. Eagles quarterback Phil Jurkovec, a Notre Dame transfer, threw for more than 300 yards in four of his last five games.

Mississippi State at No. 2 Alabama, 7 p.m., ESPN

The Crimson Tide suffered a major loss last week when wide receiver Jaylen Waddle suffered a fractured ankle that likely will sideline him for the season. With Waddle’s help (25 receptions, 22.3 yards per catch), Alabama enters the weekend third in FBS in scoring (48.4 points per game) and total offense (566.4-yard average).

The Bulldogs have the SEC’s No. 1 pass defense (192.3 yards per game) to try to neutralize quarterback Mac Jones (78.8%, 1,905 yards, 12 TDs), but their offense scored 30 points the last three games and has turned the ball over 16 times on the season.

No. 17 Indiana at Rutgers, 3:30 p.m., FoxSports1

Would you believe that when darkness falls Saturday in Piscataway, the Scarlet Knights could own at least a share of first place in the rugged Big Ten East?

Rutgers marked the return of head coach Greg Schiano by breaking its 21-game conference losing streak with the help of seven takeaways against Michigan State. Junior Isiah Pacheco (Vineland South) rushed for two touchdowns and the Rutgers defense posted 12 tackles for losses, most by a Big Ten team in Week 1.

The Hoosiers gained just 211 yards of total offense last week against Penn State, had the ball for less than 20 minutes, and still won, 36-35, in overtime with some late magic from quarterback Michael Penix Jr.

Rutgers running back Isaih Pacheco rushed for two touchdowns against Michigan State in last week's upset victory.
Carlos Osorio / AP
Rutgers running back Isaih Pacheco rushed for two touchdowns against Michigan State in last week's upset victory.
No. 4 Notre Dame at Georgia Tech, 3:30 p.m., 6ABC

The Fighting Irish quieted the doubters last week with a 45-3 road rout of Pittsburgh behind 312 passing yards and three touchdown throws from Ian Book, and now must keep their collective minds from wandering to Clemson next week. The Irish are in the top 10 nationally in total defense and points allowed. The Yellow Jackets, who gave up 73 points to Clemson two weeks ago, have lost 18 turnovers, 16 more than Notre Dame.

No. 5 Georgia at Kentucky, noon, SEC Network

The Bulldogs had last week off to regroup following their 41-24 loss at Alabama and would like to go into next week’s matchup against Florida with a strong performance under their belt. They’ll need a better effort from Stetson Bennett, who threw three interceptions against the Crimson Tide. The Wildcats have nine interceptions but their offense stalled out last week, managing just 145 total yards in a loss to Missouri.

Quarterback Sam Ehlinger gives Texas a chance against Oklahoma State and its stout defense.
Tim Warner / MCT
Quarterback Sam Ehlinger gives Texas a chance against Oklahoma State and its stout defense.
Texas at No. 6 Oklahoma State, 4 p.m., Fox29

This will be a compelling duel of one of the best defenses in FBS vs. an offense directed by one of the nation’s top quarterbacks. The Cowboys have allowed only 12 points per game, a 19.3% mark in third-down conversion defense (third in FBS), and three passing touchdowns. Longhorns quarterback Sam Ehlinger has accounted for 24 TDs, and his 17 scoring throws are second nationally. He also is seventh in FBS in total offense at 354.8 yards per game.

Expatriate of the week

Junior cornerback Avery Young, who starred in football and basketball at Coatesville High School, played a key role for Rutgers in last week’s season-opening win at Michigan State. The 6-foot, 198-pound Young was in on 10 tackles and forced two fumbles, and also returned two punts for 12 yards. Young’s brother, Aaron, a sophomore running back, rushed nine times for 23 yards and caught two passes for the Scarlet Knights.