Three potential difference-makers have just been called up to the Majors from AAA - depending on how your fantasy league works you may be able to grab them already. Even if you can’t, you should probably be hovering over the waiver wire until they become available.

Jeff Clement, C/DH, Mariners - Although Clement has been blocked for years at catcher by the recent extension given to Kenji Johjima (to much gnashing of teeth and rending of garments), he is now going to get a shot to be the Mariners’ full-time DH, thanks to the utter suckiness of current Ms DH Jose Vidro ( .211/.269/.326). Some people are wondering if Clement is going to displace Vidro right away, but I say that he is - I just can’t see the Mariners calling up Clement (and releasing Greg Norton) just to have him ride the pine - and given Clement’s insane AAA line this year of .397/.535/.692, you have to take a chance on him if you at all have space on your roster.

Max Scherzer, SP, Diamondbacks - The DBacks are riding high with baseball’s best record, and had no particular plans or even need to call up Scherzer any time soon, but his insane performance at AAA so far this year - a 1.17 ERA and 38 K in 23 IP - forced them to call him up. Initially they were just going to use him as a reliever, but his stunning performance on Tuesday night, retiring all 13 batters he faced, 7 by strikeout, while hitting 98 mph on the gun, forced the Dbacks to take Edgar Gonzalez out of the rotation to make room for him. He will be starting on Monday, and should be good for strikeouts, and with the Dbacks’ offense, wins, right from the get-go.

Darrell Rasner, SP, Yankees - This may be a less obvious pick, given that Rasner has not been too exciting in previous major league tours, posting a career 4.13 ERA in 52.1 career IP. But with the Yankees finally finding a way to make Philip Hughes disappear (claiming an oblique strain in order to DL him), Rasner looks certain to get the call, and he has been pitching out of his mind this season at AAA Scranton, going 4-0 with a 0.87 ERA in 5 starts, while striking out 27 men in 31 innings. While he is certainly not going reproduce those numbers at the major league level, the 27-year-old hurler looks to have turned a corner this season, and with the Yankees offense behind him he should be good for wins, some strikeouts, and a decent ERA right away, and should be able to help almost any fantasy pitching staff at the back end.

When the Mariners traded for oft-injured Nationals 2B Jose Vidro over the winter, it raised a lot of eyebrows. When the M’s announced they’d be using Vidro as a DH, everyone laughed. Everyone, that is, except Seattle fans.

Vidro had always been an above average hitter — compared to other second baseman. But compared to other designated hitters, he fell short. He had no power. None. And his career on base percentage of .365, while good, had been declining in recent years.

In short, Vidro was old, slow and getting older and slower. It looked like an awful acquisition.

So Vidro and the Mariners’ front office should feel pretty good about the today’s story on ESPN.com, which describes the Vidro experiment as an unlikely success:

After a modest first half in which his .286 batting average was supported by a paltry .349 slugging percentage, Vidro has been scorching since the All-Star break. His .387 second-half batting average (55-for-142) is second best in the American League, behind only Chone Figgins (.388). Overall, Vidro is hitting .318 with an on-base percentage of .384.

Vidro says his legs, battered by years on the unforgiving Astroturf of Montreal, feel better than they have in many seasons (he credits diligent work by Seattle’s training staff for his improved health).

But is Vidro’s hot streak for real? And does a good batting average make up for a total lack of power?

The folks over at the blog U.S.S. Mariner aren’t sold on Vidro:

There’s a lot to be wary of. For someone with no speed, he’s getting a lot of infield hits (7.1% right now) and his batting average when he puts the ball in play is a ridiculous .346.

As the blog points out, speedy players often have high IFH%. But Vidro is no speedy player. Quite the opposite. The U.S.S. Mariner has crunched the numbers and they say that over the last few months, Vidro has been very, very lucky. Shallow flies have been dropping. Grounders have found holes. He’s been lucky:

If Vidro got hits at his career rate, and his infield hit rate was a little more reasonable, here’s his line: .286/.351/.355

Not bad. Is it enough to justify $6 million per over two years? Take a look at these other DHs and their 2007 OBP and salary:

David Ortiz .436 / $13 million
Travis Hafner .379 / $4 million
Gary Sheffield .383 / $11 million
Jim Thome .408 / $15.6 million
Frank Thomas .374 / $5.5 million
Sammy Sosa .307 / $500,000

If you just look at OBP, Vidro looks like he’s getting paid fairly. Of course, Papi, Pronk et. al would probably be quick to point out that their slugging numbers are much better than Vidro’s. And they’d be right.

So was Vidro a good acquisition? If he stays hot, yes. But don’t hold your breath.