If the first-place Los Angeles Dodgers continue to hold off the San Francisco Giants and defend their National League West crown, Roberto Hernandez will likely be one of the big contributors. The veteran right-hander, acquired Aug. 7 when Josh Beckett could no longer pitch through a left hip injury, attempts to pay more dividends Tuesday when Los Angeles kicks off a five-game road trip with the first of two against the Arizona Diamondbacks. With Beckett apparently finished for the season, Hyun-Jin Ryu (leg) on the disabled list and Zack Greinke battling an elbow issue, Hernandez - 1-1 with a 3.18 ERA in three starts with the Dodgers - has delivered.Los Angeles, which has won four of its last six games, welcomed the return of Hanley Ramirez on Sunday after the shortstop missed 14 games with a right oblique strain. "It's going to be good to have (Ramirez) back in there, obviously," manager Don Mattingly told mlb.com. "We're not going to try to be that cautious. We're just going to play him. Obviously, we're not going to run him into the ground. If there's something going on or he's not feeling good, we'll give him a break." Arizona enters the series with a bit of momentum after taking two of three from San Diego over the weekend and gives the ball to Trevor Cahill, who is unbeaten in his last four turns.TV: 9:40 p.m. ET, SportsNet LA (Los Angeles), FSN ArizonaPITCHING MATCHUP: Dodgers RH Roberto Hernandez (7-9, 3.78 ERA) vs. Diamondbacks RH Trevor Cahill (3-8, 4.54)Hernandez allowed four runs (three earned) and eight hits in five innings of a 4-1 loss to the Padres on Wednesday after yielding three runs combined in his first two starts with Los Angeles. ''I didn't feel it was my best,'' the 33-year-old Dominican told reporters through a translator. ''... I just wasn't able to get in a rhythm. I was getting outside of the zone a little bit.'' Hernandez defeated Arizona 4-2 on July 27 when he permitted two runs in seven innings of his penultimate start with Philadelphia.Cahill received a no-decision after allowing two runs and six hits in 6 1/3 innings of Arizona's 3-2 loss at Washington on Wednesday. The 26-year-old Californian recorded his fifth straight quality start and hasn't allowed more than two runs in his last four turns while going 2-0 with a 2.33 ERA during that span. Cahill faced the Dodgers four times in 2014 - two relief appearances totalling four hitless innings and a pair of starts in which he yielded 12 runs (11 earned) over eight innings combined, including a 7-5 loss on March 22 in Australia.WALK-OFFS1. Los Angeles 1B Adrian Gonzalez is hitting .400 with three home runs, seven doubles, 17 RBIs and eight runs scored in 60 at-bats since Aug. 7.2. Arizona C Miguel Montero went 4-for-9 with a homer, double, four walks and four RBIs in the series against the Padres.3. The Dodgers lead the season series 10-4, including 4-2 at Chase Field.PREDICTION: Dodgers 9, Diamondbacks 8