Prediction, Preview, and Odds
#3959 Arizona Diamondbacks vs.
#3960 Colorado Rockies
Friday, May 21, 2021 at 8:40pm EDT
Written by Nick Raffoul

This article covers a past game!

View upcoming games.

The Arizona Diamondbacks will head on the road to Coors Field for the opening game of their National League West series clash versus the Colorado Rockies on Friday night.

Prior to closing up its series against the Los Angeles Dodgers on Thursday, the Diamondbacks had dropped four in a row and seven of their last eight games to fall to 18-26 on the year. Meanwhile, Colorado remains in last place in the NL West standings with a 15-29 overall mark, 13 games back of the division lead. The Rockies also enter this series riding a losing streak of their own, dropping five straight games after managing just a single run in three games on the road in San Diego against the Padres.

Can Colorado bounce back in a big way at Coors Field against the Diamondbacks on Friday?

Frankoff battling to earn spot on DBacks' pitching staff

Rookie right-hander Seth Frankoff is scheduled to toe the rubber on the road at Coors Field for the series opener in Colorado on Friday. Frankoff is back in the big leagues with the DBacks in 2021 and will get a chance to make his second spot start of the season. He failed to make the roster out of spring training after posting a 6.17 ERA and .154 WHIP in four appearances (three starts).

The 32-year-old bounced around the minor leagues between 2010 and 2018 before heading overseas and showcasing his ability in the KBO. In his lone start of the season, he surrendered just two earned runs on three hits in 4 ⅔ innings of work versus the Washington Nationals. The DBacks’ right-hander enters with a 0-0 record to go along with a 3.86 ERA so far this season. With another strong performance, it could be hard for manager Torey Lovullo to deny Frankoff a spot on the staff moving forward.

Marquez trending in the right direction following win vs. Reds

Colorado is scheduled to hand the ball to right-hander German Marquez, who is trying to turn things around after a rough start to the season. The Rockies’ right-hander is 2-4 with a career-high 5.56 ERA through nine starts but snapped a personal three-game skid with a strong performance his last time out. Marquez limited the Cincinnati Reds to just four runs in six innings of work, striking out eight batters and walking three on the night.

Most of the damage against Marquez this season came in an eight-run outburst against the San Francisco Giants on May 4th when he recorded just two outs in an ugly loss. He’s pitched into the sixth inning or later in six of his nine starts, but has also struggled with free passes, issuing 5.36 walks per nine innings of work.

Despite that mark, there are still reasons to be encouraged about Marquez’s prospects for the remainder of the season. The Rockies’ right-hander has been victimized by a whopping .346 BABIP, which should start to trend back towards the league average as the season wears on. Marquez also owns a 4.60 xERA and a 4.02 xFIP, suggesting that some positive regression could be on the horizon for him soon.

In 18 games (17 starts) versus the Diamondbacks, Marquez owns a lifetime 4-5 record and a career 4.26 ERA, spanning 99 ⅓ innings of work. According to Baseball Savant, current Diamondbacks are batting .333 in 148 plate appearances off of the Rockies’ right-hander heading into Friday’s matchup.

Best Bets for this Game

Full-Game Side Bet

Insiders Status:


Marquez has performed admirably for the Rockies this season. Aside from his hiccup against the Giants, he has been one of the team’s most consistent starters this season but there should be some value on the DBacks in this spot. Frankoff is essentially pitching for his MLB career right now. After defecting back to the United States from Korea, the right-hander failed to make Arizona’s roster out of the spring but is getting a second look after posting a strong 2021 debut. With Arizona’s offense mired in a two-week-long slump, look for the Diamondbacks to break out at hitter-friendly Coors Field this weekend. Take Arizona to come out on top on the road in this NL West battle on Friday.

Prediction: Arizona Diamondbacks +124

Full-Game Total Pick

Insiders Status:


It’s hard not to like the over in this spot. Marquez has been putting on a lot of baserunners this season and balls are finding safe landing spots once they get put in play, which is good news for the total here. Heading into Thursday’s series finale against the Dodgers, Arizona’s offense had scored two runs or fewer in seven of its last eight games, so the DBacks should be due for some positive regression soon and this looks like a good spot for that to happen. Not only are the DBacks due for runs but they also have some solid numbers against Marquez coming into this game. Take the over with confidence at Coors Field on Friday night.

Prediction: Over

Written By Nick Raffoul , "Nick Raffoul"

Shortly after graduating with an Honors in Business Administration, Nick turned his attention from traditional stocks and bonds to investing in the performance of sports teams. And has now joined our team here at Winners & Whiners. Nick uses a combination of advanced stats and historical data to create sports investment models to identify value and generate consistent profits. Let Nick win for you.