Taking another look at the Orioles' rotation depth

The news on right-hander Chris Tillman from Sunday was concerning. He never even made it to his planned bullpen session, shut down after about 10 long-toss throws before he was planning to take the mound.

So Tillman, who was on the disabled list from Aug. 24 to Sept. 11 last season with right shoulder bursitis, continues to have shoulder discomfort. He got a platelet-rich plasma injection in December and now Sunday's setback, detailed here and here.

Tillman returned from that issue last year and went 1-1 with a 3.79 ERA in his last four regular season starts and then started the American League wild card game in Toronto.

So where would the Orioles turn to replace Tillman? That answer could be very different depending on whether he missed a start or a few rather than a month or a few. Or longer in a worst-case scenario.

We've written here previously about the starting pitching depth within the organization. Here is another look, in alphabetical order, at eight internal candidates:

Jayson Aquino: The 24-year-old lefty from the Dominican Republic is having a solid spring. Over nine innings, he's allowed six hits and one run with a walk and nine strikeouts.

During the 2015 calendar year, Aquino was traded three times. Then, in December of that year, he joined a fourth different team when St. Louis claimed him off waivers from Cleveland. On April 7, 2016, the Orioles acquired Aquino from the Cardinals for cash considerations. So he has gotten around a lot the last two years. In 20 games at Double-A Bowie last season, Aquino went 5-10 with a 3.90 ERA. In five games for Triple-A Norfolk, he went 2-0 with a 2.08 ERA. Aquino pitched 2 1/3 scoreless in the majors last year.

Jason García: It is still pretty amazing that this now 24-year-old right-hander pitched in the majors in 2015, making the leap from low-A ball as a Rule 5 pick. That would be the equivalent of an O's prospect pitching on the staff in 2014 for Single-A Delmarva and the next year for Baltimore. García did okay, too, posting an ERA of 4.25 for the Orioles.

García did not fare as well last year pitching in the rotation at Bowie, going 6-10 with a 4.73 ERA in 124 innings. He walked 54, fanned 71 and gave up a .291 average. His fastball velocity was often 92-93 mph, but touched 96-97. His slider looked to be ahead of his changeup. Is his long-term future in the bullpen?

Joe Gunkel: He was Boston's 18th-round selection in 2013 after a career at Division II West Chester (Pa.). Gunkel was traded to the Orioles in June 2015 for outfielder Alejandro De Aza. He spent most of 2016 in the Triple-A Norfolk rotation and seemed close to a call-up a few times, but it never came.

He started last season with Bowie, going 0-3 with a 3.66 ERA in four starts. Then over 24 starts for Norfolk, he went 8-11 with a 4.08 ERA. Gunkel's fastball works between 88-92 mph, and while he doesn't throw the ball by many hitters, his control has been outstanding. He averaged 1.15 walks per nine innings with Norfolk (18 in 141 1/3). In 2015 between Single-A and Double-A, he went 11-6 with a 2.68 ERA and averaged 1.68 walks per nine innings. Gunkel, who has been compared to the Orioles' Tyler Wilson, has a career walk rate of 1.57, a strikeout rate of 7.45 and a 1.12 WHIP.

Chris Lee: Had he not gotten hurt in late May last season, the 24-year-old Lee would have probably pitched in the majors at some point last year. The Orioles acquired him from Houston in May 2015 and quickly put him on a fast track toward the majors.

Lee has made 15 appearances the last two seasons for Bowie, going 9-2 with a 3.02 ERA and 1.187 WHIP, but his season ended late last May due to lat and shoulder issues. Even though his fastball can touch the mid-90s, he has not been a big strikeout pitcher. In 89 1/3 innings last year, he walked 33 and fanned 45. But the results have been solid and if he proves this spring the injuries are in his rear-view mirror, his major league debut is very possible at some point this summer. Lee has had a strong camp, allowing two runs and five hits in eight innings with a walk and eight strikeouts. Could that major league debut be moved up to April?

Logan Verrett: This right-hander was an Orioles Rule 5 draft pick in December 2014 (along with García). He pitched well in spring training of 2015, but was claimed by the Rangers late in camp and later sent back to the Mets.

He did not have a strong 2016 for the Mets, going 3-8 with a 5.20 ERA over 91 2/3 innings. Left-handers hit .276 against him and right-handers hit .291. The 26-year-old Verrett pitched solidly in relief last year with an ERA of 2.84. But in his 12 starts for New York, he went 1-6 with an ERA of 6.45.

Verrett is 4-10 with a 4.65 ERA and 1.378 WHIP in 53 major league games, including 16 starts. He's 35-16 with a 3.93 ERA and 1.215 WHIP in five minor league seasons. He has an option remaining, so he could start the year at Triple-A.

Tyler Wilson: Wilson was drafted out of Virginia in the 10th round of the 2011 draft. He stayed under the radar as a pitching prospect for a few seasons. But then he showed up in Baltimore during 2015 and did well, going 2-2 with a 3.50 ERA. Last year for the Orioles, he went 4-6 with a 5.27 ERA. Over 94 innings, he gave up 15 homers among 110 hits with 24 walks and 55 strikeouts. Without a blazing fastball, Wilson always seems to get labeled as having marginal stuff, but it comes with an abundance of poise, smarts and guts. Wilson has a 5.87 ERA in three games this spring.

Mike Wright: For the last two seasons, Wright has mostly excelled at Triple-A and yet struggled in the majors. This makes him no different than many other young pitchers around the game. But the question now for the 27-year-old right-hander is will he be able to become more consistent at the major league level?

In 2015 and 2016, he pitched to an ERA of 2.63 for Norfolk. But with the Orioles, he went 5-9 with a 5.88 ERA, allowing 21 homers over 119 innings. He definitely has solid stuff with a mid-90s fastball, but his secondary pitches have been inconsistent. A mid- to late-inning relief job could be in his future, but he remains a starter now. If it ever clicks for him, that ERA could take a nosedive, but so far it hasn't. Wright has a 4.70 ERA in three spring outings.

The Orioles have come a long way with Wilson and Wright since that 2011 draft, developing them into pitchers that made the 40-man roster and reached the majors. Now we need to find out if they can improve off their 2016 seasons and stay there.

Gabriel Ynoa: Like Verrett, he was acquired from the Mets for cash considerations. He spent 2016 mostly with Triple-A Las Vegas, going 12-5 with a 3.97 ERA in 154 innings. In the Pacific Coast League, lefty batters hit .331 against Ynoa and right-handed batters hit .241. He's been described as a pitcher with a solid sinker and changeup and fastball that can reach the mid 90s. In 136 career minor league games, he is 59-30 with a 3.36 ERA, 1.17 WHIP, 1.5 walk rate and 5.6 strikeout rate.

In the WBC: O's catcher Welington Castillo has sure come up big, along with Manny Machado, for the Dominican Republic. He made a nice catch of a short-hopped outfield throw home and tagged a runner out trying to score in the last of the ninth Sunday to keep the game tied 3-3 versus Colombia. He then singled in two runs in the 11th to break that 3-3 tie as the DR went on to win 10-3 in 11 innings to advance to the second round of pool play in San Diego. Castillo has caught every inning for the DR squad and has driven in at least a run in each game.

Machado was named the MVP of Pool C after he had two hits in their opening game, two hits against the USA and one hit yesterday. He made several stellar defensive plays as well.

Team USA advanced with last night's 8-0 win over Canada to improve to 2-1. Starter Danny Duffy went the first four innings and five pitchers teamed on a four-hitter with 15 strikeouts. The O's Mychal Givens pitched a scoreless fifth with two strikeouts for the Americans.

O's players stats in the tournament:

* Machado is 5-for-14 (.357) with a double, homer and two RBIs and a 1.043 OPS
* Castillo is 3-for-12 (.250) with a double, homer and five RBIs.
* Adam Jones is 4-for-14 (.286) with two doubles, two RBIs and a walk-off hit
* Mychal Givens has allowed two runs and three hits in two innings with five strikeouts
* Jonathan Schoop is 5-for-17 (.294) with a homer and three RBIs