When a young pitcher suddenly forgets how to throw a baseball, it's disturbing. You have a hurler who is humming along, start after start, sometimes over the course of multiple seasons, before he loses his location, movement, control, and velocity. It's obviously a cause for concern.

Sometimes, injuries are to blame. Sometimes, it just goes away on its own, and no one is sure if it's ever going to come back.

For Philadelphia Phillies righty Aaron Nola, there was a little of both last year, as the right-hander stumbled to a 4.78 ERA in 20 starts before missing the last two months of the season with an injury to his pitching elbow. Luckily, the ailment wasn't serious enough for him to need surgery, but it did raise red flags coming into 2017.

And for the first couple months of this season, the question marks surrounding Nola didn't go away. In his first three starts, he had a 4.50 ERA and opponents were batting .317 against him. He then went on the disabled list for about a month with back stiffness and upon returning, he still wasn't sharp, posting a 5.63 ERA in his next three starts to finish off May.

But June has been a different story. Nola's good stuff has returned, as evidenced by his performance against the Seattle Mariners on Tuesday in which he went seven innings and gave up two runs on five hits with four walks and nine strikeouts. After a three-inning start on May 31 that pushed his ERA up to a season-high 5.06, he has since lowered it to 4.13 in his last five outings.

In June, Nola has a 3.24 ERA in five starts, with 35 strikeouts and 11 walks in 33 1/2 innings. Over his last two starts, he's lowered his ERA by half a run. He has 17 strikeouts in his last 14 1/3 innings and, most importantly, his stuff has looked like this.

When Nola is on, his two-seamer darts back across the inside part of the plate against left-handers and catches the back-door against righties, and his curveball and changeup are plus pitches, as well. This is the Nola that everyone saw in his first 12 starts last season, when he put up a 2.65 ERA and 0.99 WHIP. Opponents batted just .209 against him over that stretch.

And then, suddenly, his stuff disappeared. He couldn't get anyone out. In his last eight starts of 2016, he had an ERA of 9.82 with a WHIP of 2.06 and an opponents' batting average against of .355. He then went on the shelf with his elbow issues.

Worries about his health have certainly eased. He threw 114 pitches on Tuesday, the most he's ever thrown in any start, and his nine punchouts against the Mariners tied his career high. But the durability concerns won't completely go away until he finishes the season totally healthy.

All signs point to him being a reliable starting pitcher for the rest of 2017, which is great news for fantasy owners who have him stashed on their benches. And it's also a welcome sight for the Phillies, who haven't seen much go right in a starting rotation that was supposed to be the strength of their team.

Jerad Eickhoff (4.93 ERA) and Vincent Velasquez (5.58 ERA) are both on the disabled list and have underperformed when healthy. When Nola is on his game, he is a bonafide No. 2 starter who can flash ace-type stuff, something the Phils and fantasy owners want to see continue through the rest of the season.