In many ways, the Phillies' 10th loss of the 2021 season was defined by, well ... the No. 10.

The day began with manager Joe Girardi saying he would be "thrilled" if Vince Velasquez could go four innings and "just keep us in the game" at hitter-friendly Coors Field.

Making his first start of the season, Velasquez did exactly that, though it ultimately wasn't enough in the Phils' 5-4 walk-off loss in Friday's series opener against the Rockies. Velasquez departed with the game tied at 2, and while the Phillies later took a 4-2 lead, the bullpen faltered late.

For Velasquez, the No. 10 represented a step in the right direction. For the offense and the ‘pen, however, it was more of an imperfect 10.

Let's take a deeper dive on Friday's loss:

1-for-10

Velasquez cruised through the first three innings despite the leadoff man reaching in both the first (a Didi Gregorius error) and second (walk). The right-hander escaped both frames unscathed, as the Rockies went just 1-for-10 with three strikeouts when Velasquez was working from the stretch.

In his three relief appearances this season, Velasquez walked six of the 13 batters that he faced out of the stretch. His lone walk Friday came from the windup.

"He's been working on it hard with [pitching coach] Caleb [Cotham]," Girardi said. "It's been a focus of his work. Again, I thought Vinny threw the ball really well tonight, and that's key, because the most important outs are when you're in the stretch. So you have to make sure you're locked in there."

Velasquez was certainly locked in from the stretch for the first two innings, before turning in a 10-pitch third inning that left his pitch count at a manageable 38. Unfortunately for the Phils, he promptly served up a leadoff home run in the fourth to Trevor Story, who hadn't homered in 29 straight games dating to last season. While Story's shot came on a changeup that was buried in off the plate, C.J. Cron followed two batters later with another solo homer -- this one on a 91.5 mph fastball right down the heart of the plate.

The Rockies then hit back-to-back singles off Velasquez, who served up four of his five hits in that troublesome fourth inning. Still, he buckled down to retire the next two hitters to complete four frames.

"My job is just to go out there and pitch and get outs," Velasquez said. "You're going to mature through situations like that. You're going to walk guys, you're going to learn how to make those adjustments. ... You better find a way and learn how to make pitches."

0-for-10

Though the Phillies held a 4-3 lead in the top of the eighth, they had a chance to add on following a one-out double by Nick Maton. Instead, Matt Joyce grounded out and Roman Quinn popped out to end the threat.

That capped an 0-for-10 night with runners in scoring position. It dropped the Phillies' season average to .222 with runners in scoring position. They're just 3-for-39 (.077) with 12 strikeouts with RISP over their last six losses.

"We have not hit particularly well all year, and it's probably a good reason we're 9-10," Girardi said. "We have to have better at-bats with runners in scoring position. Sometimes it takes a bloop to get people going, and all of a sudden, you take off. So hopefully that can happen and we can score more runs."

10.13 ERA

After posting a 7.06 bullpen ERA in 2020 -- the highest by any team in the Majors in the last 90 years -- Philadelphia's 'pen had actually been a strength through the first few weeks of the ‘21 season. The past few games have been a different story.

Phillies relievers have a 10.13 ERA over the last three games, allowing 13 runs (12 earned) off five homers in just 10 2/3 innings. They allowed one run each in the seventh, eighth and ninth innings Friday, capped by Raimel Tapia's walk-off homer off Héctor Neris.

"When you ask for five innings out of your bullpen, especially in a ballpark like this, chances are you're going to give up a couple runs," Girardi said. "It's unfortunate that we gave up three."

Of course, the recent struggles have come without 2021 newcomers Archie Bradley (strained left oblique) and José Alvarado (COVID-19 protocols).

"It's definitely more difficult. We're asking people to step up and maybe get a few more outs than they're used to doing, but that's what you've got to do," Girardi said. "It's got to be next man up. You go through injuries all year and guys have to step up, so it's important that they do that."