Castillo (0-1) struck out eight but allowed four runs on nine hits and a walk over 5.2 innings in a loss Monday against Colorado.

EDGE Analysis

Castillo continues to show exceptionally nasty stuff. He induced 17 swinging strikes on 111 pitches and now has 22 strikeouts in just 16.1 major league innings. He has been too wild to go deep in games, however -- even though he walked just one batter Monday, he threw only 10 first-pitch strikes to 27 hitters, which contributed to the whopping nine hits he allowed. But Castillo is young, and if he can tighten up his control, his already electric arsenal will prove all the more effective.

Castillo struck out nine Milwaukee hitters over 5.2 innings Wednesday, allowing two runs on five hits and three walks in a no-decision.

EDGE Analysis

He left with the lead and the Reds went on to win, but not before their bullpen blew the victory for Castillo. Nonetheless, the young righty has impressed with his velocity and showed strong control in the minors, so he offers tantalizing upside. However, the schedule does him no favors, as Castillo is lined up for a start against the Rockies at Coors Field on Monday.

Manager Bryan Price said Castillo will stay in the Reds' starting rotation for now, C. Trent Rosecrans of The Cincinnati Enquirer reports.

EDGE Analysis

Castillo earned a spot start Friday after Asher Wojciechowski was designated for assignment, and the 24-year-old prospect pitched well enough to keep pitching for the big club. He allowed two runs on five hits and five walks while striking out five in his major-league debut. His next start is scheduled to come Wednesday against the Brewers.

Castillo (0-0) allowed two runs on five hits and five walks while striking out five across five innings, but received no decision Friday against the Nationals.

EDGE Analysis

In his first big league start, Castillo was fortunate to get away with putting 10 runners on base, including a pair of homers, but was in line for the win until the bullpen blew a 5-2 lead. It's very possible that his time in the rotation will quickly come to an end, as Brandon Finnegan (shoulder) is expected to return from the disabled list in the near future. He'll make his next start Wednesday against the Brewers.

Castillo was recalled from Double-A Pensacola to start Friday's game against the Nationals.

EDGE Analysis

As expected, Castillo will step in to fill the rotational void left when the Reds designated Asher Wojciechowski for assignment Sunday. Although Castillo has impressed with Pensacola this season, compiling a 2.58 ERA, 1.00 WHIP and 81:13 K:BB over 80.1 innings (14 starts), he faces one of the better offenses in baseball in his major-league debut, so it wouldn't be very wise to expect much of the 24-year-old. Southpaw Amir Garrett was optioned to Triple-A in a corresponding roster move.

Castillo will be recalled from Double-A Pensacola on Friday to start for the Reds later that evening against the Nationals, Mark Sheldon of MLB.com reports.

EDGE Analysis

After the Reds designated Asher Wojciechowski for assignment Sunday, it was expected the organization would go with one of its more experienced arms at Triple-A Louisville to fill the void in the rotation, but it will instead be the 24-year-old Castillo who gets the call. While Castillo, one of the Reds' top pitching prospects, has been electric for Pensacola this season, compiling a 2.58 ERA, 1.00 WHIP and 81:13 K:BB over 80.1 innings, it may be unwise to expect quality results from him as he makes his major-league debut against one of baseball's top offenses. Even if Castillo is able to steer clear of an implosion, he may only receive one more start beyond Friday's, as Brandon Finnegan (shoulder) will make a third rehab start at Triple-A on Wednesday and could be ready to come off the 60-day disabled list by the end of June or early July.

Castillo could be in line for a promotion to Triple-A Louisville soon, C. Trent Rosecrans from the Cincinnati Enquirer reports. He has a 2.08 ERA, 0.90 WHIP and 25:4 K:BB at Double-A Pensacola in 30.1 innings so far.

EDGE Analysis

Castillo, acquired in the Dan Straily trade, really impressed teammate Devin Mesoraco when Mesoraco did his rehab stint with Pensacola. "Castillo is almost equally impressive," said Mesoraco, who caught two of Castillo's starts for the Blue Wahoos. "(He has) really good plus stuff, obviously, but he throws so many strikes. He throws a lot, a lot of strikes with all three pitches."

Castillo was optioned to Triple-A Louisville on Wednesday, one of 16 players cut from the Reds' major league camp, MLB.com reports.

EDGE Analysis

While Castillo was impressive in spring training, the plan all along was for him to begin the season in the minors. "Probably the first thing is that he hasn't done anything to take our optimism away," Reds manager Bryan Price said. "What we had to do, considering innings and opportunities we had for length, is we had to pare it down to who are the most likely. We had to rank them in order to give them regular time and regular innings. I just felt with his limited Double-A time that it made more sense for him to start the season in player development and maybe be one of those quick-jump guys should we need him early in the year."

Castillo threw two scoreless innings against the Rockies in Sunday's spring training game, with his fastball clocking in around 98 mph, the Cincinnati Enquirer reports.

EDGE Analysis

Castillo is still on track to work at Double-A to begin the season, and the Reds plan on keeping him as a starter. The fastball has never been in question, so the focus this year will be how much his secondary offerings improve.

Castillo is headed to Cincinnati as part of the deal to acquire pitcher Dan Straily, MLB.com's Joe Frisaro reports.

EDGE Analysis

Castillo was marvelous for High-A Jupiter in 2016, posting a 2.26 ERA and 0.96 WHIP over 117.2 frames. The 24-year-old right-hander eventually earned a promotion to the Double-A level, where he is expected to start for Cincinnati in 2017. He was Miami's No. 2 prospect, although that's not saying much, as the Marlins have a bottom-three system in baseball. Castillo possesses a fastball that consistently hits the upper-90s and can touch triple digits, but needs to improve his secondary pitches in order to realize his mid-rotation ceiling. He was recently converted from the bullpen to the rotation, so he has more upside than the typical 24-year-old at Double-A.