MINNEAPOLIS -- Reds coaches and interim manager Jim Riggleman have been talking about what could be causing pitcher Luis Castillo to be less effective in 2018 than he was during his dominant rookie campaign last year. It was certainly a topic in the dugout Friday, when Castillo pitched a career-low one inning and allowed five earned runs vs. the Twins.
Now, the Reds are hoping to carve out some time so Castillo can make the changes.
Castillo worked with pitching coach Danny Darwin last year at Double-A Pensacola. Bullpen coach Ted Power has been around the right-hander since his callup last June. And coach Derrin Ebert has been breaking down the video.
"They all agree that his arm angle has changed a little bit,' Riggleman said Saturday. "His hand is maybe not getting on top of the ball like it needs to. What that does, is it causes the ball to flatten out instead of sink. Hitters love that when the ball moves [flat] across the plate instead of having some sink. It's kind of running right into their barrel."
After pitching to a 3.12 ERA and 1.08 WHIP in 15 starts in 2017, Castillo is 1-3 with a 7.85 ERA and 1.67 WHIP through six starts this season. Data collected by Statcast™ highlights how Castillo isn't throwing as effectively as he had previously.

In 2017, batters had an average exit velocity of 84.9 mph. This season, it's 89.7 mph. His hard-hit rate, which was 30.1 percent last season, has risen to 39.4 percent in '18. A line-drive/fly-ball rate of 35 percent in '17 is now 45.7 percent in '18.
And in a statistic that underscores what Riggleman mentioned, hitters barreled Castillo up on 3.5 percent of his batted balls last year, and now it's 10.6 percent.
Castillo's velocity has also dipped. His four-seam fastball averaged 97.5 mph last season, and it's 95.5 mph this season. His two-seam fastball, which averaged 96.9 mph in 2017, is down to 95.1 mph. A slightly lower velocity can be deceptive, however. The Reds have played in a lot of cold weather, including on Friday, and since Castillo was in the Minors at this time last year, there is no data to compare to last April.

Not all of Castillo's metrics are down this season. His whiff/swing rate has improved this year -- from 28.7 percent in 2017 to 31.4 percent in '18. But a majority of Castillo's swings-and-misses have come when he throws his still-nasty changeup.
Castillo was primarily a four-seam fastball pitcher when he came up, and he developed a two-seamer in the middle of last season. Now, he uses the two-seamer more often than the four-seam pitch -- 35.2 percent to 25.5 percent. But the heat map below shows that the two-seam fastball has often been sitting over the middle of the plate.

Riggleman wouldn't mind skipping Castillo's next turn in the rotation so the right-hander can work on his delivery and arm angle. But the next team off-day is Thursday, and Castillo is scheduled to pitch Wednesday vs. the Brewers.
"It would have been nice to let him take a step back and get two bullpen sessions with the coaches and get him straightened out," Riggleman said.
There's another question the Reds are trying to answer as well: Could Castillo be tipping his pitches to hitters?
"I mentioned that last night in the dugout," Riggleman said. "We've got to look closely at his tape and see if we can see him doing anything different on pitches. I don't know if we've got an answer for that yet."
Six times on base, that's a lot
Reds first baseman Joey Votto was among the hitters that helped get Castillo off of the hook in a 15-9 win over the Twins on Friday. Votto reached safely six times, tying a career high he previously set on May 18, 2013.
Before Votto, Sean Casey was the last Reds player to reach base six times in a nine-inning game (a 24-12 Reds win on May 19, 1999 in Denver). The last Reds player to achieve the feat twice was Johnny Bench, both times vs. the Cubs at Wrigley Field (June 14, 1975 and July 22, 1979).

Worth noting
• Infielder Cliff Pennington cleared waivers and was sent outright to Triple-A Louisville.