Here's a look at the top offensive performers in each league for the week ending June 30:
Andrew Lambo, Indianapolis
(.500/.609/1.056, 6 G, 9-for-18, 1 2B, 3 HR, 8 RBI, 4 R, 5 BB, 2 K)
Acquired by the Pirates (along with starter James McDonald) from the Dodgers for Octavio Dotel in 2010, Lambo is having a breakout season at age 24. The right fielder hit for the cycle on April 9 and made his Triple-A debut two months later. He has seven homers, 21 RBIs and a .314/.410/.700 line in his first 20 IL games, including three blasts last week. Lambo, who had never hit more than 18 long balls in any season, has 21 already in 2013.
Pacific Coast League
Grant Green, Sacramento
(.480/.500/.960, 6 G, 12-for-25, 3 2B, 3 HR, 6 RBI, 6 R, 1 BB, 2 K)
A first-round pick in 2009, Green has long been a top prospect in search of a position -- first he was a shortstop, then an outfielder and now he's at second base in his second Triple-A campaign with the River Cats. He's been a solid hitter all along and is having his finest season at the plate this year. The 25-year-old has multiple hits in seven of his last eight games and ranks second in the PCL with 60 runs scored in 75 games. Now the Athletics' No. 3 prospect, Green's .380 on-base percentage is the highest of his career.
Brad Glenn, New Hampshire
(.400/.464/.800, 7 G, 10-for-25, 2 2B, 2 HR, 7 RBI, 8 R, 3 BB, 8 K)
Glenn is in his second full season with the Fisher Cats and has seen dramatic improvement at getting on base. After drawing 29 walks last year, the 26-year-old outfielder has 34 free passes already this season and has seen his OBP rise from .291 to .360. He only walked three times last week, perhaps largely because he was busy ripping hits. Glenn went deep twice during the week and has scored at least one run in eight of his last nine contests.
Kevin Kiermaier, Montgomery
(.414/.433/.828, 7 G, 12-for-29, 2 2B, 2 3B, 2 HR, 3 RBI, 5 R, 0 BB, 4 K, 1 SB, 1 CS)
After being named the best defensive player in the Rays organization last year, Kiermaier is proving he can swing the bat as well. The 23-year-old center fielder had at least one hit in each of his seven games last week, leads the Southern League with a .323 average and nine triples and ranks second with 59 runs scored. Kiermaier clubbed two of his four home runs last week and flirted with the cycle against Tennessee on Sunday, going 3-for-5 with a long ball and a double.
Whit Merrifield, NW Arkansas
(.688/.688/.875, 4 G, 11-for-16, 3 2B, 0 3B, 0 HR, 9 RBI, 3 R, 0 BB, 1 K, 1 SB)
Merrifield batted just .179 in April and May, but closed out a potent June performance with four straight multi-hit games to finish the month with a .380 mark. The 24-year-old outfielder collected 11 hits and nine RBIs in the four contests as the Naturals jumped out to an early lead in the second-half North Division race at 7-4. Though the sample size is small -- he missed a month with a hamstring injury -- Merrifield has posted some extreme splits this season: he's hitting .312 at home but just .176 on the road and has batted .309 in 30 night games and only .097 in nine matinees.
Harold Riggins, Modesto
(.375/.500/.833, 7 G, 9-for-24, 2 2B, 3 HR, 7 RBI, 9 R, 4 BB, 11 K, 1 SB)
After batting .225 in the first half of the season, Riggins -- a South Atlantic League All-Star with Asheville last year -- is off to a hot start in the second half, posting a .361/.511/.778 line in 11 games. Strikeouts have been the big problem for the 23-year-old N.C. State product throughout his brief career: he ranks third in the Minors (and leads the Cal League) with 115 in 71 games this year. Though he still fanned 11 times last week, he also bashed three homers, bringing his total to 12 on the season.
Michael Ohlman, Frederick
(.407/.467/.704, 7 G, 11-for-27, 5 2B, 1 HR, 8 RBI, 3 R, 3 BB, 7 K)
Ohlman earned Carolina League honors for the second straight week, boosted by a four-game multi-hit streak during which he collected five extra-base hits and drove in eight runs. Having played just 44 games, the 22-year-old catcher lacks the plate appearances to qualify for the league batting title, but his .318 average would rank third on the circuit while his .426 on-base percentage would be second-best. Ohlman hit .356 with five homers and 17 RBIs in 25 June games and seems poised to make the jump to Double-A Bowie.
Florida State League
Anthony Garcia, Palm Beach
(.429/.484/.821, 7 G, 12-for-28, 5 2B, 2 HR, 4 RBI, 8 R, 1 BB, 7 K, 1 SB)
Garcia's introduction to the Florida State League was a rough one; the 21-year-old outfielder hit .232 in April and .149 in May. He blistered the circuit's pitchers in June, however, batting .385 with seven long balls in 17 games. Garcia closed out the month with hits in his final eight games, including seven extra-base knocks, and scored in six of seven games. After collecting seven doubles in his first 57 games, Garcia had five last week.
Jeff Holm, West Michigan
(.385/.484/.731, 7 G, 10-for-26, 1 2B, 1 3B, 2 HR, 5 RBI, 6 R, 5 BB, 1 K, 1 SB)
At 24, Holm is one of the older players in the Midwest League. He's unlikely to be there much longer after his performance last week. The Michigan State product reached base in 33 straight games between Opening Day and May 18 and after a brutal seven-game hitless streak at the start of June during which he went 0-for-26, has gotten on base in each of his last 14 contests. Though he's hit fewer homers (eight) than one might like from a first baseman, Holm is slugging .482 and has made good contact with just 42 strikeouts (and 32 walks) in 72 games with the Whitecaps.
South Atlantic League
Tom Murphy, Asheville
(.440/.462/1.080, 6 G, 11-for-25, 4 2B, 4 HR, 14 RBI, 7 R, 1 BB, 6 K)
Sometimes it's difficult to understand why a player has yet to be promoted, although it can be tough finding playing time for everyone if an organization has a glut of strong players at a given position. In any case, Sally League pitchers have authorized your correspondent to urge the Rockies to send Murphy to Class A Advanced Modesto after capturing weekly honors for the third time this year. The 22-year-old backstop clubbed four more homers and drove in 14 runs over six games last week. He leads the league in OPS (1.095), slugging (.690) and RBIs (65) despite playing in only 56 games. Rockies: enough!
New York-Penn League
Dan Gulbransen, Tri-City
(.500/.517/.821, 7 G, 14-for-28, 3 2B, 2 HR, 8 RBI, 8 R, 1 BB, 2 K)
A 16th-round pick out of Jacksonville University in 2012, Gulbransen's second stint with the ValleyCats is going much better than the first, during which he hit .218. This season, the 22-year-old outfielder is batting .415 and has driven in a run in seven of his last eight games. Gulbransen collected multiple hits in five of his seven outings last week and has helped Tri-City to an 11-3 start, best in the New York-Penn League, which he leads in batting, hits and RBIs.
Yasiel Balaguert, Boise
(.348/.483/.783, 7 G, 8-for-23, 1 2B, 3 HR, 9 RBI, 8 R, 6 BB, 6 K)
Other Yasiels (namely fellow Cuban defector Yasiel Puig) have drawn more notice in baseball lately, but Balaguert had quite a week of his own for the Hawks. The 20-year-old outfielder closed out the week with three long balls and seven RBIs over his last four games. Balaguert plated three more runs on Sunday to give him 22 in 17 games -- no one else in the Northwest League has more than 15. Of Balaguert's nine extra-base hits, eight have come with runners on base.
Appalachian League (for the period of June 20-30)
Derrick Loveless, Bluefield
(.355/.444/.742, 9 G, 11-for-31, 2 2B, 2 3B, 2 HR, 2 RBI, 5 R, 5 BB, 3 K, 1 CS)
Loveless made his third-ever Appy League game a memorable one, going 4-for-5 with a pair of solo homers at Pulaski on June 23. Four of his next six hits went for extra bases as well, giving him a .742 slugging percentage after nine games. Despite the strong start, the 20-year-old has only two RBIs -- he's 11-for-21 (.524) with the bases empty and 0-for-10 with runners on base.
Pioneer League (for the period of June 20-30)
Phil Ervin, Billings
(.353/.476/.588, 9 G, 12-for-34, 0 2B, 1 3B, 2 HR, 7 RBI, 4 R, 7 BB, 7 K, 3 SB)
A first-round pick (27th overall) by the Reds last month, it hasn't taken long for Ervin to make an impact in the Pioneer League. The Samford product opened his pro career with hits in seven straight games and collected four RBIs and his first long ball in his third outing with the Mustangs. Despite going hitless over the weekend, Ervin drew four walks in two games at Great Falls and is already demonstrating a thoughtful approach at the plate.