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Felix Hernandez is 11-3 with 137 strikeouts in 139 2/3 innings this season for Seattle.

By Orestes Destrade, ESPN

Any true baseball fan has to love Monday's matchup between Seattle ace Felix Hernandez and Toronto rookie sensation Ricky Romero.

Romero comes into the start 8-4 with a 3.44 ERA, and he may soon be relied upon as Toronto's ace if the Jays do indeed trade Roy Halladay. On the other side, Hernandez (11-3, 2.45 ERA) has arguably been the most dominant pitcher in the American League this season. It took him five years to meet the expectations thrust upon him by baseball scouts who predicted greatness.

Hernandez is not just a dominant ace; he's an ace with three devastating pitches. These credentials are rare in a pitcher. That's why there was so much expectation when he came up as a 19-year old. Scouts thought he would be the next Dwight Gooden, a young guy with an overpowering fastball. But it takes a little while to hone one's skills at the big league level. Word spreads around the league when you know a guy is that good. Hitters study his quirks, and learn to take advantage of them. They expect him to throw hard. He's a tall pitcher who loves to dominate the zone with low, moving fastballs. If I'm up at the plate, I'll be looking for a pitch to hit up in the zone. I wouldn't commit to a knee-high fastball. If you commit to that pitch, chances are you'll end up getting fooled with a slider.

That's how well King Felix has adjusted in this league. He gives hitters too many things to think about up at the plate. You can't go up there hacking at his pitches, or else he'll blow you away with ease.

Romero is a top candidate for this year's AL Rookie of the Year, but his road to get there was a bumpy one. Romero was selected sixth overall by the Blue Jays in 2005, but had struggled a bit before hitting the majors. He dealt with shoulder problems in his first years as a minor leaguer and then developed control problems as he progressed through the farm system. He walked 55 batters in Double-A New Hampshire last season, but has been able to settle in nicely this year since getting the call to the majors. From what he's shown, he looks to be headed toward a nice career. But you can't fast forward with a talented arm.

Romero isn't a dominating pitcher like Hernandez. He doesn't have nasty stuff, but he has the ability to consistently throw strikes. The league is still scuffling to figure him out. The best way to do so is to gather plate appearances against him. After about 20 at-bats, they should have a good feel for how he works. The next 20 at-bats will be how the pitcher discovers new ways to approach each hitter. It's all a learning process that Romero will become accustomed to with more experience.

We're witnessing a matchup between Cy Young and Rookie of the Year candidates. Yes, this is the kind of matchup you just have to see.

Past Baseball Tonight Clubhouses: July 23 | July 22 | July 21 | July 20 | July 19

WEB GEMS SCOREBOARD

This season, "Baseball Tonight" will be tracking Web Gems. We'll publish a leaderboard on the Baseball Tonight Clubhouse page each Monday. In addition to listing the leaders in appearances (both players and teams) on "Baseball Tonight," we'll offer up the leaders in Web Gem points.

Web Gem points will be calculated by awarding five points for the night's top defensive play, four points for second, three for third, two for fourth and one for fifth. Scoring will be based on the Web Gems from the last "Baseball Tonight" show to air on a given night.

Web Gem points leaderboard
Jack Wilson	33
Carlos Gomez	27
Brandon Inge	26
Orlando Hudson	21
Three tied	20

Web Gem appearances leaderboard (players)
Brandon Inge	Detroit	Third base	9
Jack Wilson	Pittsburgh	Shortstop	8
David Wright	New York Mets	Third base	8
Carlos Gomez	Minnesota	Center field	7
Ryan Zimmerman	Washington	Third base	7

Web Gem appearances leaderboard (teams)
Philadelphia	23
Washington	22
Cincinnati	22
Pittsburgh	22
New York Mets	20

ON DECK: MONDAY'S BEST MATCHUPS

Yankees at Rays, 7 p.m. ET

The Rays could make either serious headway in their pursuit of the Yankees or dig themselves a nearly insurmountable hole in the AL East. Tampa Bay trails New York by 6½ games in the division. A.J. Burnett has won his past four decisions; James Shields hasn't been involved in a decision since July 1, a string of four consecutive starts.

Dodgers at Cardinals, 7:15 p.m. ET, ESPN

The Cardinals limp in, having sacrificed first place in the NL Central to the Cubs by losing five of seven. But St. Louis sends its ace out against the Dodgers. Chris Carpenter went 3-0 with a 1.86 ERA in July. Albert Pujols is hitting .357 in his career against Randy Wolf, but has never taken the lefty deep.

Astros at Cubs, 8:05 p.m. ET

Carlos Zambrano has kept his ERA below 4.00 since the start of June, but now he is adding wins, capturing three in a row. Wandy Rodriguez has won his past four starts and five consecutive decisions.

For the rest of Monday's schedule, click here.