Robert Murtha (34), Estancia High's senior tailback, is the Newport-Mesa career rushing leader. (KEVIN CHANG, Daily Pilot / October 1, 2012)

Opening league play in football is always big. Opening league play against a cross-town rival just builds up the game even more.

That is the situation Estancia and Costa Mesa are in this week. The Battle for the Bell between the two schools is Friday at Jim Scott Stadium at 7 p.m.

The rivals start Orange Coast League play against each other, rather than close it as they did last season. That game last year turned out to be for the outright league title as both teams went into it undefeated in league.

Last year marked the first time in the history of the rivalry that the Eagles and Mustangs played with a league title at stake in the final league game. Estancia won the 45th meeting, 28-14, and finished perfect in league for a second straight year.

The 46th meeting is crucial because each program wants to get off to a good start in league.

Before the season, Coach Mike Bargas said the Eagles' toughest league opponents were Costa Mesa and Laguna Beach. They face those teams in back-to-back weeks.

"If we go 2-0 in those two first games, then everything falls into place," said Bargas, who is trying to lead Estancia to a third straight league crown, a first for the program.

Costa Mesa (2-3) will try to be the first league team to knock off Estancia (3-2), ranked No. 8 in the CIF Southern Section Southern Division, in quite some time.

The Eagles have won their past 11 league contests. Their last setback in league came three years ago against Laguna Beach.

The Mustangs have had time to prepare for Estancia, which leads the rivalry, 26-18-1. They had a bye last week, while the Eagles played on the road and beat Sonora, 24-18.

The extra week to get ready for the Battle for the Bell might bode well for Costa Mesa. In the past seven matchups, Estancia has had a bye twice before the big game and it won each time.

Bargas said he prefers to play the rivalry game right away, rather than at the end of the regular season.

Wally Grant, in his second year as the head coach of the Mustangs, said he doesn't care when Costa Mesa and Estancia square off.

"What I have to get across to my kids is that [the Estancia] game is no more important than the Calvary Chapel game, the Godinez game, the Saddleback game and the Laguna Beach game," Grant said before the season. "Yeah [it was hard for my players to digest last year], because it was brought into this program that if you beat Estancia and lost the rest of your games, you were successful. That's just asinine.

"If we lose to Estancia, that doesn't make or break our season, because we still can go to the playoffs and we can still win CIF. I'll win CIF and lose to Estancia every year."

Three years ago, early in the football season, my sports editor, Steve Virgen, mentioned a kid named Robert Murtha.

He had seen him on YouTube and then seen him play live at Estancia. Murtha wasn't on varsity back then, but the freshman stood out to Virgen and he called the running back a special player.

Virgen was right.

Three years later, Murtha is now the Newport-Mesa career rushing leader. He has 4,398 yards on the ground, surpassing Costa Mesa's Binh Tran, who rushed for 4,333 yards from 1991-93.

Murtha, who is in his third year starting on varsity, is 561 rushing yards away from cracking Orange County's all-time top-10 list. With five regular-season games left in his senior year, Murtha is on track to put his name in the county record book.

Coach Dan Glenn is hoping senior Tristen Thompson doesn't miss a second straight year with the Newport Harbor girls' volleyball team because of a knee injury.

An anterior cruciate ligament injury sidelined Thompson during her junior season.

Glenn said Thompson planned to visit the doctor Monday to get her latest injury checked after her left kneecap dislocated during the Sailors' Battle of the Bay loss at Corona del Mar on Saturday.

"There's probably too much swelling to make a decision," Glenn said about whether Thompson, an outside hitter, will miss the rest of the year. "It's tough to have a one-year senior captain go down like that [in the second set], especially with the kind of night she was having [against CdM with 11 kills and one error]. Unfortunately with athletics, everything is not always fair."

david.carrillo@latimes.com

Twitter: @DCPenaloza