(Photo credit: Rick Scuteri-Imagn Images)

Zac Gallen will start the opening contest of the Arizona Diamondbacks' three-game series against the Chicago Cubs on Friday afternoon with a purple, baseball-seamed bruise on his right shoulder after being struck by a line drive in his latest start.

The Diamondbacks as a whole can relate.

The D-backs are in their roughest stretch of the season as they head to Chicago to conclude a six-game Midwestern road trip.

Arizona was outscored 28-9 while losing two of three games in Milwaukee to start the week, and the Diamondbacks have lost six of their past nine overall. They dropped 13-2 and 13-1 blowouts on either side of a 6-2 win over the Brewers.

'The two games we lost here, we have to be better,' Arizona manager Torey Lovullo said after the Thursday rout. 'This is a hard game, and I think we're making it harder on ourselves.'

Gallen (1-1, 3.14 ERA) is set to oppose fellow right-hander Colin Rea (3-1, 4.61) of the Cubs on Friday.

The D-backs have not had a starting pitcher go more than five innings since Gallen went 5 2/3 in a no-decision against the Toronto Blue Jays on April 18. Arizona has given up at least 10 runs four times in the nine games since.

To save bullpen arms, catcher James McCann made mop-up appearances in each of the Milwaukee losses. He has taken the mound in four games this season.

'I hate having a position player pitch games,' Lovullo said. 'Probably one of my least favorite things in baseball. But ... you ask a position player to go out there and give you that extra inning so you're all gassed up for the next city.'

Through it all, Arizona first baseman Ildemaro Vargas has hit. He had two singles on Thursday to extend his season-opening hitting streak to 23 games, tied with Edgar Renteria for the second longest in the majors to open a season since 1940. Ron LeFlore hit in 30 straight for the Detroit Tigers in 1976.

Vargas has hit in 26 straight dating to last September, the longest active streak in the majors and tied with Paul Goldschmidt (2013-14) for the second longest in franchise history behind Luis Gonzalez's 30-game stretch in 1999.

The Cubs sputtered a bit after they had a 10-game winning streak end last weekend, but they began this week by winning the last two of three games in San Diego. Pete Crow-Armstrong homered in Chicago victories on Tuesday and Wednesday.

Crow-Armstrong hit a two-run shot in the Cubs' 5-4 win on Wednesday. He also drove in a sixth-inning run on a groundout to first with runners on second and third and one out against hard-throwing left-hander Adrian Morejon.

That gave the Cubs a lead they never lost, a win cemented as Hoby Milner became the fifth Cub to record a save this season when he struck out Ramon Laureano to end the game.

'Pete making contact against Morejon ... that's hard to do,' Cubs manager Craig Counsell said. 'I probably like that better than the home run at-bat.

'I know it's probably illegal to say, even though I love the home run, but he put a ball in play when we needed to get a ball in play. It got us a run in a really tough matchup.'

The Cubs have scored 169 runs, which ranks third in the majors, and they are in the top five in most major offensive categories. Their 42 homers are tied for fourth, and their .353 on-base percentage is tops.

Tasking with slowing the Chicago bats is Gallen, who won't miss a start despite an early exit in his Saturday outing against the Padres in Mexico City.

Freddy Fermin's third-inning liner caught Gallen in the throwing shoulder. Gallen completed the inning before exiting the game with Arizona leading 4-0.

Gallen struggled against the Cubs last year, going 0-2 with a 9.00 ERA in two starts. In his career vs. Chicago, he is 3-3 with a 4.03 ERA in eight starts.

Rea is coming off his worst outing of the season, when he was tagged for six runs on six hits in 3 1/3 innings in a defeat against the Los Angeles Dodgers on Saturday. He has no decisions and a 5.68 ERA in five career appearances (four starts) vs. the Diamondbacks.

--Field Level Media