A native of British Columbia, the 24-year-old Paxton is 6-feet-4 and 220 pounds. His body weight is very well distributed. He has long arms and legs that help in his pitching mechanics.
MLB.com ranks Paxton fifth among Mariners prospects and No. 74 overall. He joins right-handed starter Taijuan Walker (No. 1/No. 4 overall) and fellow left-hander Danny Hultzen (No. 2/No. 8 overall) in forming an outstanding trio of future Seattle starting pitchers.
Few teams have the pitching depth Seattle boasts. It was a factor that helped the Mariners add Kendrys Morales from the Angels in exchange for Jason Vargas for some much-needed offensive punch.
I was able to see all five of Paxton's starts in the Arizona Fall League.
Due to a knee injury, Paxton missed some time during this past season. The AFL provided the opportunity to make up for lost innings.
His performance in Arizona was rather inconsistent. He began the season well, but had some hiccups thereafter.
Paxton finished with a 5.68 ERA and a 1.58 WHIP. In 12 2/3 innings, he allowed 14 hits. Opponents batted .275 against him.
It was his ability to miss bats and strike hitters out that was the most impressive component of his fall work. He struck out 16 hitters while walking only six.
Paxton attended the University Of Kentucky, where his stock as a potential professional pitcher increased in each of three seasons.
As a freshman, he was used out of the bullpen. Midway through his sophomore year, Paxton was moved to the rotation. He ended the season making 11 starts and compiling a 2.92 ERA.
Following a junior year when Paxton threw 78 1/3 innings and struck out 115 hitters, scouts really began to take notice.
In the 2009 First-Year Player Draft, the Toronto Blue Jays selected Paxton in the supplemental round with the 37th overall pick.
Paxton did not sign a professional contract.
Paxton wanted to return to Kentucky for his senior year. However, it was determined he had engaged a player representative and he was ruled ineligible to return to college.
So instead of pitching as a senior for Kentucky, Paxton signed a contract to play professionally with the Grand Prairie Airhogs, an independent Texas team.
Paxton's choice of an independent league to continue his pitching development was not unique. Prior to their arrival in affiliated organizations, pitchers Luke Hochever and Max Scherzer refined their skills for the same Grand Prairie club.
During his season with the Airhogs, Paxton went 1-2 with a 4.08 ERA. Most importantly, professional scouts were watching.
The Mariners selected Paxton with their fourth-round pick in the 2010 Draft. Paxton signed a contract and began pitching for the Mariners at two classifications in 2011.
Pitching at high Class A Clinton, Paxton started 10 games and threw 56 innings. He gave up only 45 hits, but he walked 30 batters. The result was a WHIP of 1.339. He did, however, show an ability to miss bats, striking out 80.
Paxton was moved to Double-A Jackson, where he threw another 39 innings in seven more starts. His command and control improved markedly as he walked only 13 while becoming more dominant.
Last season, Paxton returned to Jackson, where a knee injury cost him time on the mound. He started 21 games, finishing with a 9-4 record.
His ERA and WHIP both went up due to inconsistency in his command and control.
Overall, he was more hittable because he fell behind in counts. He finished the season throwing 106 1/3 innings with an ERA of 3.05 and a WHIP of 1.411.
Paxton has issues similar to many young pitchers. There are good starts and there are some that are not so good.
The first thing I noticed is that it takes some time for Paxton to get his engine revved up and his body comfortable on the mound. Sometimes, a couple of innings.
When he follows through with his long, slender arm and finishes his pitches, Paxton is very solid. He induces swings and misses or gets called third strikes because his pitches change the eye level or the balance of the hitter. Pitching downhill, he hides the ball well. With his size, the pitch is on top of the hitter quickly.
However, when he loses rhythm and his mechanics change, he fails to repeat that sound delivery and good mechanics.
When he fails to repeat his delivery, he loses control. He has trouble commanding his pitches. He falls behind in counts. He serves up pitches that get too much of the plate. He gets hit. Or he is wild enough to walk hitters. In a few short moments, his game escapes.
Basically, Paxton's best pitches are his two- and four-seam fastballs.
Paxton gets good, downward life on his two-seamer. His four-seamer is a bit straight.
He throws the fastballs anywhere between 90 and 95 mph. I have seen him add and subtract velocity in the same start or even in the same at-bat. In one game, he began the first inning throwing 90 mph and finished his third and final inning of work consistently at 94 mph.
I think both his slider and curveball will continue to be solid secondary pitches, especially the curve. Both need refinement, but the curve is fairly well advanced. Both will benefit by Paxton showing more confidence in his ability to control those pitches.
Patience will be required to help the strong, long-armed southpaw refine and harness his command. He has to continue to face quality hitters and find ways to repeat his delivery.
I'm confidant with continued repetition, Paxton has the skill to step into the middle of the Mariners rotation and help his club win games.
Bernie Pleskoff has served as a professional scout for the Houston Astros and Seattle Mariners. Follow follow him on Twitter at @BerniePleskoff. This story was not subject to the approval of Major League Baseball or its clubs.