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4/12/2013 12:15 P.M. ET

Scout's belief helps Rosenthal's transition to mound

Former Seattle pitcher uncovers converted shortstop at college tournament

It's one thing to watch video or watch a baseball game on television and see a particular player or pitcher in action. It's quite another to scout the individual in person.

I had seen plenty of video of St. Louis Cardinals pitcher Trevor Rosenthal. Like so many others last postseason, I watched the television in awe as he pitched like a seasoned veteran.

Scouting Rosenthal in person, I saw his fearless mound demeanor and take-charge attitude come to life. I scouted two games in which he pitched against the Arizona Diamondbacks.

I was able to experience the discomfort of hitters as they tried to solve Rosenthal's pitching puzzles. I was able to feel the electricity in the air when he took the mound and began the deliberate execution of his game plan -- go right after the hitter -- especially during his first appearance in the series.

But I'm getting ahead of myself. It's best to briefly share a bit about how Rosenthal has become one of the finest young pitchers in today's game. How, at just 22 years old, he earned his way to becoming a major component of the Cardinals' pitching staff.

Former Seattle Mariners pitcher Aaron Looper is an area scout for the Cards. In the spring of 2009, like a number of other scouts, he attended the Kansas Jayhawk Community College Conference Tournament in Wichita, Kan. A converted shortstop named Rosenthal pitched 1 1/3 innings for Cowley County Community College in that tournament. Even though Rosenthal did not have a deep history as a pitcher, the 6-foot-2, 220-pounder got Looper's attention.

There are times a scout only gets to see one inning from a pitcher. Or one at-bat from a hitter. Regardless, the scout has to evaluate what he has seen. He has to look at the mechanics of the player or pitcher and translate them to potential.

Looper became an advocate for Rosenthal. That's an important part of being a scout. If a scout believes in a player, the scout shares his enthusiasm and belief with his front office. A scout must trust his own training, competency and judgment.

Looper trusted his judgment and shared his opinion about Rosenthal based upon what he saw. Not just on what he heard. What he saw.

The Cardinals selected the right-handed Rosenthal in the 21st round of the 2009 First-Year Player Draft.

The baseball archives of Cowley County Community College said this about Rosenthal: "Player that could see playing time as a pitcher or at shortstop. Has a great deal of potential." True. No doubt about it.

Rosenthal made his professional debut for the Gulf Coast League Cardinals in rookie ball. He threw only 24 innings in 14 games, all out of the bullpen. Rosenthal's ERA was 4.88. Walking 10 while striking out 26, he continued to develop his high-90s fastball.

The following two seasons, Rosenthal worked as a starter in the Cards' system, showing great promise with high-velocity fastballs and a developing repertoire of secondary pitches.

Last season, however, the rocket fuel kicked in and Rosenthal was launched. He pitched at Double-A Springfield and Triple-A Memphis, where he went a combined 8-6 in 20 starts. Rosenthal threw to a combined ERA of 2.97 in 109 innings. He gave up only 78 hits and 42 walks, while striking out almost nine hitters per nine innings.

Then, on July 18, Rosenthal become the 2,000th Major League player in St. Louis Cardinals history.

Rosenthal's rookie season for the parent club was highlighted in the postseason. He appeared in seven games, pitching 8 2/3 innings without yielding an earned run. Rosenthal faced 30 hitters, striking out half of them. He walked only two and gave up only two hits. It was a remarkable performance under pressure.

I have been asked if Rosenthal is better as a starter or reliever. Frankly, he has enough repertoire, command, control and mound demeanor to start. That might be where Rosenthal has the greatest value. However, he would make a tremendous closer, as well.

Rosenthal faced three hitters in the first game I saw. He threw 13 pitches, nine for strikes, all were fastballs. Rosenthal used no secondary pitches. No pitch was thrown at less than 97 mph. He touched 100 mph twice. The ball just exploded at home plate. Rosenthal showed absolutely no strain or effort achieving his velocity. Generally using the lower portion of the strike zone, in one instance, Rosenthal "climbed the ladder" and elevated his last pitch, resulting in a swing and miss.

I wondered if Rosenthal could pitch from the bullpen in back-to-back games.

The following night, Rosenthal entered the game in the eighth inning of what turned out to be a 16-inning D-backs victory. He pitched two innings.

The second appearance was totally different than the night before. Rosenthal used his fastball, a curve and a changeup. His fastball wasn't as dominant. Rosenthal's secondary pitches were effective, but he ended up facing 10 batters and throwing 39 pitches. He returned to earth. Rosenthal was touched for three hits, a run and a walk.

In both outings, I was quite surprised at the ease with which Rosenthal could repeat his delivery. His arm action and his release point were consistent and very sound mechanically. Rosenthal was able to finish his pitches with excellent follow-through that almost made it look like he was playing catch with Yadier Molina, his catcher. He uses his strong legs to anchor very good balance.

Refining pitches like his changeup with the help of teammate Fernando Salas and gaining wisdom from others, Rosenthal can use his curve or changeup as an "out pitch" to end an at-bat. They complement his incredibly effective fastball.

Looper believed in what he saw in Rosenthal. With very good reason.

Bernie Pleskoff has served as a professional scout for the Houston Astros and Seattle Mariners. Follow @BerniePleskoff on Twitter. This story was not subject to the approval of Major League Baseball or its clubs.