Vince Velasquez took the ball for the fifth time this season on Tuesday night and delivered a performance that was much like many others during his tantalizing Phillies tenure.

Throughout his four-plus innings of work, Velasquez was, at times, awe-inspiring and dominant as he overpowered Arizona hitters with his high-octane fastball. Yet, in the end, his performance was once again underwhelming.

There were flashes of brilliance, particularly in the second inning, when he struck out the side. On this pitch, he delivers a wicked 96.9 MPH four-seam fastball on the outside corner to Daniel Descalso.

Good luck with that:

https://twitter.com/long_drive/status/988923768624967680?s=21

Here, he comes back with a 96.5 MPH four-seamer to freeze Nick Ahmed:

https://twitter.com/long_drive/status/988924221949607936?s=21

Still, he put his team in an early hole, couldn’t hold the lead when he got it, and his 86 pitches failed to get him through the fifth-inning. Velasquez wasn’t necessarily ineffective last night, but he once again looked like a promising talent who still can’t quite seem to put it all together.

To be fair, the enigmatic 25-year-old right-hander has been markedly better in several aspects than he was a year ago. His average fastball velocity is up a tick, and that has shown up in an increase from 8.5 K/9 last season to 10.38 this year, which is more in line with his 2016 strikeout numbers. Perhaps more encouragingly, his walk rate is well down from 4.25 BB/9 from a year ago to 2.42, and he has done a better job overall of keeping the ball in the yard, despite his two hiccups in the third last night. He’s been a bit unlucky as opponents’ BABIP has risen from from .303 in 2017 to .347 this season, and his 3.40 xFIP suggests he’s been measurably better than his 4.50 ERA.

That’s all fine and well, but legitimate concerns remain.

Undoubtedly, it is an absolutely exasperating experience to watch him breeze through the first inning, overwhelm hitters in the second, and throw a mere six pitches to get through the fourth when it’s juxtaposed with a rocky third inning and laborious fifth.

What the hell is the problem, you ask?

From this perspective, Velasquez’s over-reliance on his fastball continues to haunt him. His first 11 pitches of the game last night were fastballs before he got Paul Goldschmidt to end the first by popping out on a slider. I guess you could argue that this is his way of establishing an aggressive attack mentality, or “setting the tone,” if you will, but I find it troubling. Some say that his reliance upon the fastball is about bravado – that he simply believes he can overpower everybody – but I’m not so sure. Two-plus seasons of uneven results should, theoretically, have proved such a thesis false. I don’t think he glares into the eyes of a hitter while proclaiming, “You get a piece of it, I’ll let you name it,” as if he were Rick Vaughn.

To me, it’s his inability to consistently control and trust his secondary pitches, which he struggles to command, that increases his reliance upon the fastball. Throwing a fastball on average at 95 MPH is generally good. In fact, he averaged 96 mph on his four-seem fastball last night and topped out at 98.5 MPH. That should be problematic for the opposition, and, at times, it is. Here’s the problem: He only threw four changeups, five sliders, and 17 curveballs compared to 60 fastballs. He can overpower hitters, but he can’t consistently keep them off balance, and that’s why his performances from start to start, hell, even inning to inning, are often erratic.

On the home run allowed to Alex Avila, he gets ahead with a decent two-seam fastball. He follows that by missing with a four-seamer, and then with a 1-1 curve. Now what? The lack of trust and command in his secondary pitches causes him to predictably revert back to his fastball, and, well, a 95.6 MPH fastball traveled 418 feet and it was 1-0 Arizona.

Here’s the sequencing:

That fourth pitch? The location is, uh, not ideal, particularly if the hitter assumes the likelihood that a fastball is coming.

Jarrod Dyson, he of 13 career home runs in 1,763 career at-bats, followed up Avila’s blast with a 383-foot homer. This time, Velasquez gets ahead with two four-seam fastballs and revs it up to 97 MPH, but misses. He then tries the curve and misses. Hmm, I wonder what he’s going to do next? This time a 94.3 MPH two-seamer doesn’t get proper run, and a dominant start quickly morphed into a typically turbulent one.

Here are the blasts:

https://twitter.com/ballparkvids/status/988950258876125185?s=21

I can hear some of you out there now.

“Just turn him into a closer, because, like, he throws hard and shit.”

Not so fast. The presumption that simply condensing his pitch load will optimize his fastball and allow him to flourish because he’s so “nasty” isn’t necessarily correct. If he’s not getting late action on pitches, as is sometimes the case, I don’t believe that his curveball, while decent, is good enough on its own to make him an elite late-inning reliever. He still needs to develop a functional change up or other secondary pitch that will keep hitters honest. While he’s still relatively young and may be able to accomplish this, I’m concerned that there hasn’t been marked improvement in those pitches at this point.

For now, when it comes to Velasquez, continue to expect more extreme highs and lows, and hope for further development… or some luck.