LOS ANGELES — The Los Angeles Dodgers won’t let back-to-back clunkers dim what has been a thoroughly impressive first half.The reigning champions enter play Sunday as the owners of MLB’s best record (61-35), the highest batting average (.263), slugging percentage (.435) and team OPS in baseball (.779). They’ve hit the second-most home runs in the National League (126) behind the Washington Nationals’ 136. Their pitching has been equally as good, despite being without Blake Snell and Tyler Glasnow for most of the season. The Dodgers’ rotation has logged the most innings in the NL (533 1/3) and ranks top three in opponent average (second, .215) and strikeouts (third, 513).They could be even stronger in the second half. Four key pieces are on their way back. Edwin Díaz (bone chips in right elbow) started a rehab assignment with Class A Ontario on Saturday where he gave up a hit and struck out two in an inning of work. He’ll need multiple outings, but the Dodgers are optimistic he could return perhaps as early as during the team’s 10-day road trip to kick off the second half.Snell faced live hitters for the first time since undergoing bone chip removal surgery in his left elbow and is on schedule to start a rehab assignment sometime next week. The Dodgers would like him to stretch out to at least five innings or 75 pitches before activation. That also applies to Glasnow (back spasms), who is behind Snell, but did take a significant step in throwing his first bullpen Friday at Dodger Stadium. Kiké Hernández (oblique strain) is targeting a return on July 28 during the Dodgers’ first homestand after the All-Star break.A team is only as good as its depth, and the Dodgers have relied on theirs heavily so far. Let’s take a look at some of the unsung heroes who have helped propel Los Angeles to another impressive first half.LHP Justin WrobleskiIt sounds silly to call Wrobleski underrated considering he was named to the National League All-Star team as a replacement on Saturday. But given how the Dodgers first planned to use him compared to how he’s wound up contributing, it’s warranted.When the Dodgers broke camp in March, they needed to minimize the workload of their starting rotation. Enter Wrobleski, who was originally set for a piggyback role while mixing in some spot starts when needed. Quickly, however, the Dodgers realized they’d need to utilize a consistent six-man rotation and inserted the 25-year-old after their first turn through. He hasn’t looked back.Wrobleski’s 2.69 ERA represents the seventh-best mark among starters in the NL. His 1.02 WHIP is tied for third-lowest, and he has the second-best walk rate through nine innings at 1.79. The league may not value wins the same as it once did, but Wrobleski’s 10-2 record as a starter gives him one of the top winning percentages, and as manager Dave Roberts acknowledged, it also speaks to his overall effectiveness.“To be able to get pitching decisions, you’ve got to go deeper in games,” Roberts said. “The ERA is stellar, innings per outing, and I just think that he’s performed enough to earn (an All-Star bid).”Evidently, the league agreed. Wrobleski will join Freddie Freeman, Max Muncy, Andy Pages and Yoshinobu Yamamoto at the Midsummer Classic in Philadelphia next week. (Shohei Ohtani was also named an All-Star, but won’t play in the game due to irritation in his left knee.)