When 17-year-old Brian Mullen went up to bat for the first time in the championship game of the Reviving Baseball in Inner Cities League earlier this month, he couldn’t quite believe he was actually playing a game at Wrigley Field. So he took his time and walked slowly to the plate and let the feeling sink in. The left handed hitting catcher thought of all the great players who had stood where he was standing.

“Babe Ruth batted in the left handed batter’s box that I batted in,” Mullen said. “I thought that was really amazing. When I came up to bat I did just take some extra time to just look around and admire it.”

Mullen and another Forest Park teenager, 17-year-old David Sims, played at Wrigley Field on Aug. 12 as part of a team called the Riots, named after Cub shortstop Ryan Theriot. The squad was composed largely of players from Walther Lutheran High School. They lost the championship of the Chicago RBI League 5-4 to the Little Bulls – named for Cubs pitcher Carlos Zambrano.

Sims, a senior at Proviso Math and Science Academy who plays on the Proviso East baseball team, joined Riots after his Proviso East team dropped out of summer play because they lacked enough players. Left without a team this summer, Sims bumped into Mullen, a middle school classmate and former Forest Park Little League teammate, at a Little League game where Mullen was watching his cousin.

Mullen invited Sims to play with the Walther Lutheran summer team. The team played in the RBI league as well as a league in DuPage County. The RBI league is sponsored by the Cubs.

The RBI program was begun by Major League Baseball in 1992 and aims to increase the participation of inner city kids in the sport. Walther Lutheran, a suburban private school, is part of the league because its team typically includes a mixture of city and suburban kids. Two years ago Mullen made an RBI all star team and played in a national tournament in California.

Sims got a late start in baseball, not really playing the game until he was 11 years old. Up to then he had played mostly soccer, but quickly took to the diamond.

“Once I started playing I was like a natural,” Sims said. “I was good at it. I just like the game. It’s fun to play. It’s my favorite sport.”

Sims, an outfielder, pinch hit and played three innings in left field during the championship game, patrolling the same ground as Cubs outfielder Alfonso Soriano.

He walked in his only at bat and scored from second base.

Standing on first base, Sims tried to soak up the surroundings.

“I was looking around the whole park,” Sims said. “It was a good feeling. I was scared at first when I was leading off the base because I wanted to stay there as long as possible.”

But soon he became less aware of where he was and concentrated on the game.

“It really wasn’t that different because after a while I wasn’t really paying attention to the stadium, I was paying attention to the game,” Sims said.

Both Mullen and Sims are Cubs fans, which made playing at Wrigley extra special to them. Mullen made sure he got there early so he could claim the Cubs third base dugout for his team.

Mullen, a 5-foot 10-inch, 185-pound catcher who is now a senior at Walther, went one for three at the plate. He smashed a line drive single to left field, walked and scored a run. Mullen also made like his favorite player, catcher Geovany Soto, throwing out a runner trying to steal second base.

Like Sims, he managed to overcome most of his awe and concentrate on the game.

“It was surprising to me how regular it felt out there,” said Mullen. “Leading up to it I thought it was going to be so different and I thought I was going to be awestruck the whole time, but once I got into the game it just felt normal.”

His father Joe, the only White Sox fan in the Mullen family, coached first base for the Riots. He said it was a pretty exciting experience to stand in that first base coaching box at Wrigley, and even better to watch his son play there.

“I know he worked very hard for a long time to get better and better and better and to see it pay off like this is going to be, I think, great for his future,” said Joe Mullen.

Mullen has always loved baseball. Both his mother Georgine, and dad play softball.

“Ever since I was born I was surrounded by some kind of baseball or softball,” said Mullen.

His grandparents, four aunts, and nine cousins joined his mother in the Wrigley Field stands. His 9-year-old cousins Mia Vilanova of Forest Park and Molly Frank of Naperville each got a chance to announce Brian’s name on the portable public address system when he came up to bat.

Mullen lives and breathes baseball.

“He is one of the most baseball oriented human beings that I know,” Don Gillingham, his coach at Walther Lutheran, said. “He’s all baseball all the time.”

Mullen’s leadership qualities were recognized this summer in the RBI League when he won an award. Cubs player Mike Fontenot handed him his plaque during an announcement to the crowd at the Cubs’ July 23 game at Wrigley against the Florida Marlins.