Improvement was the theme for most of the locals chosen on the second day of the Major League Baseball First-Year Player Draft on Tuesday.

Orange Coast College freshman pitcher Brandon Brennan became the first area player taken, when the Chicago White Sox tabbed the 6-foot-4 right-hander in the fourth round, No. 141 overall.

UC Irvine signee Timmy Lopes, a senior at Edison High in Huntington Beach, was taken in the sixth round (No. 191) by the Seattle Mariners, while UCI senior shortstop D.J. Crumlich was taken in the ninth round (No. 286) by the Pittsburgh Pirates.

OCC freshman outfielder Bijan Rademacher was taken in the 13th round (No. 404) by the Chicago Cubs.

Other draftees with local ties were former UCI player Jordan Leyland and UCLA junior outfielder Beau Amaral.

Leyland, a first baseman and designated hitter who played the 2012 season at Azusa Pacific University, was taken in the ninth round (No. 295) by the Toronto Blue Jays.

Amaral, the son of former Estancia High and OCC standout Rich Amaral, who played 10 seasons in the major leagues (1991 through 2000) with Seattle and Baltimore, was a seventh-round pick (No. 232) of the Cincinnati Reds.

For Brennan, who went 11-1 with a 1.25 earned-run average to help OCC win the Orange Empire Conference and reach the four-team California Community College Athletic Assn. championship, his selection marked a quantum leap from his senior year at Capistrano Valley High, after which he was taken in the 40th round (No. 1,220) by the Colorado Rockies in 2010.

"To be completely honest, I haven't been the most successful baseball player my entire life," Brennan, who began his collegiate career at the University of Oregon, said last month. "It wasn't until recently, with all the hard work I've put in, that I kind of accomplished a lot and succeeded in baseball."

Brennan, a first-team all-state and All-Orange Empire Conference performer, said his transition from thrower (reaching 94 mph with his fastball) to pitcher helped him move up 1,079 spots in the draft in just two years.

Brennan, who signed a letter of intent with Houston, said before the draft that he is anxious to sign and begin a professional career.

Brennan struck out 72, allowed 76 hits and walked 23 in 108 1/3 innings for OCC. He worked into the 11th inning in the Pirates' eventual state tournament elimination loss to Rio Hondo, during which he extended a scoreless innings streak to 23. In his five starts previous to that, he was 5-0 and allowed just two earned runs in 36 innings.

Brennan's 1.25 ERA ranked fourth in single-season OCC annals.

Lopes, who had been expected to fill the void at shortstop left by Crumlich, may not even compete for the Anteaters. His older brother, Christian, was drafted in the seventh round last season and signed with the Blue Jays.

Crumlich, the Big West Conference Defensive Player of the Year in 2012 who twice earned second-team all-conference honors, was also taken by Pittsburgh in last year's draft. But he was a 38th-round selection in 2011, jumping 856 spots this year.

Crumlich, a four-year starter at UCI, led the Anteaters in hits (72), runs (39) doubles (16) and batting average (.324). He posted a .969 fielding percentage and had eight stolen bases. He had 23 multi-hit games.

His career average was .296 and his 139 runs rank No. 4 in school annals. His 45 career doubles tie him for No. 5 on the school's all-time list.

He helped UCI reach the NCAA Regionals his first three seasons and was an all-tournament pick in 20011, when the Anteaters won the Los Angeles Regional at UCLA.

Rademacher, a first-team all-state and all-conference honoree, hit .349 with seven homers and 49 RBIs, the latter both team highs. Though taken as an outfielder, he wowed scouts with his strong left pitching arm, hitting 93 mph with his fastball while earning four saves down the stretch. He struck out 10 and allowed only one earned run in eight innings.

Leyland, a second-team NAIA All-American at APU, hit .419 with 22 homers, 19 doubles and 74 runs batted in in 222 at-bats for the Cougars. He was the Golden State Athletic Conference Player of the Year.

In three previous seasons at UCI, he was a collective 99 for 336 (a .295 average) with seven homers and 64 RBIs. He made the all-tournament team at the Los Angeles Regional in 2010.

Leyland was chosen in the 44th round (No. 1,350 overall) by the Tampa Bay Rays in the 2011 draft. He moved up 1,055 spots after his strong 2012 campaign. He was a 36th-round pick, also by Tampa Bay, in the 2008 draft out of San Dimas High.

Beau Amaral, a two-time all-conference honoree for the Pac-12 champion Bruins, leads UCLA (45-14 and the No. 2 national seed) into an NCAA Super Regional against TCU, beginning Friday at UCLA's Jackie Robinson Stadium. He is hitting .320 with four homers and 45 RBIs. His 61 runs lead the team.

He was a second-team Freshman All-American and he earned all-tournament honors at the 2010 College World Series, in which the Bruins were runners-up to South Carolina.

Amaral was taken in the 45th round by the Arizona Diamondbacks out of high school in 2009.

The draft continues Wednesday with rounds 16 through 40.

barry.faulkner@latimes.com

Twitter: @BarryFaulkner5