The weeks keep rolling on, and believe it or not, we are already heading into the fourth week of the Major League baseball season. Every week RotoBaller.com will guide you through your waiver wire so you can find those hidden gems that may help you win your league.

Now on to this week's additions you should consider.

Ike Davis, Pittsburgh Pirates, 1B 

19% owned CBS, 7% owned Yahoo!

The Mets finally moved first baseman Ike Davis when they traded him to the Pirates for pitcher Zachary Thornton. It was a move that needed to be made, probably sooner than it was, as the team made it known that the former prospect had fallen out of favor with the club.

Davis is off to a slow start on the heels of a terrible 2013, but there is some upside here. With regular playing time, two out of the three full seasons that Davis manned first base in Queens were very productive. As bad as last season was for him, Davis is only one season removed from a 32 HR, 90 RBI season. In this pitching dominated game, that's elite-level power production.

Davis will strikeout a bunch, and his batting average will never be anything special, but it was obvious that Davis' personality was not suited for the high pressure New York sports scene. Pittsburgh will suit him much better, and with the Pirates desperate for help at first base, Davis will not have to look over his shoulder every time he goes 0-for-4. With regular playing time, Davis could find the groove he had in the second half of 2012, and that could mean another good power season. If you need help at first, or in the power department, a speculative add of Davis makes plenty of sense.

Thus far, Davis has played three games for the Pirates, and has gone 5-for-10 with a HR, 4 RBI and 4 runs (including a grand slam last night).

Danny Espinosa, Washington Nationals, 2B 

8% owned CBS, 2% owned Yahoo!

If you have owned Ryan Zimmerman in recent years, you can count on two things from the Nationals' third bagger. He's going to give you very solid production, and he's going to get hurt and miss time. Since 2010 Zimmerman has missed at least 15 games every season, and after a hot start, Zim finds himself hurt again, this time to the tune of 4-6 weeks.

This development has forced the Nationals to move Anthony Rendon to his natural position of third base, and Danny Espinosa to return to the starting line-up as the Nats' second baseman.

Espinosa played only 44 games last season, but in the two seasons prior to that, Espinosa showed a great power/speed combination that isn't found in most middle infielders. Despite a sub-.250 batting average, Espinosa compiled 21 home runs and 17 steals in 2011, and 17 homers and 20 stolen bases in 2012. Try finding a combo like that on your waiver wire.

Espinosa will whiff a lot, and his batting average is probably going to be in the .240 range. Also, barring a set back to Zimmerman, Espinosa's days in the starting line-up are numbered. If you have an injury, or need middle infield depth, grab Espinosa and ride him until Zimmerman returns.

Henderson Alvarez, Miami Marlins, SP

38% owned CBS, 3% owned Yahoo!

It wasn't too long ago that Henderson Alvarez was a highly thought of prospect in many circles. A poor season and a few injuries later, and Alvarez has all but been forgotten, especially within the world of fantasy baseball.

Alvarez has earned a spot in the Marlins rotation for 2014. He's off to a solid start and is coming off a two-hit shutout of the Mariners. He's hot right now, and while he's nowhere near a sure thing to keep up his hot pitching, there's a lot to like here.

First, I'm not sure Alvarez has much competition for his spot in the rotation unless he completely implodes. Second, his home park has proven to be very pitcher friendly. Also, despite being in the big leagues since 2011, Alvarez is still only 24 years old, meaning he could just be finding himself as he enters his prime years. His poor showing while he played for Toronto could have been nothing more than a classic case of not being ready for the big show.

Alvarez is not without flaws, however. Playing for the Marlins means he's no lock to win games. He also hasn't shown that he'll be much help in the strikeout category, as he's fanned just 14 batters this year in 23 innings pitched. In fact, in his only full season to date in 2012, Alvarez actually had given up more earned runs (101) than strikeouts (79), over 187 innings pitched.

I won't call Alvarez a must add yet, but in NL-only leagues where pitching can be scarce, I'd keep my eye on him. If you need a pitcher, he's worth a look at least until he cools off.

Kyle Farnsworth, New York Mets, RP

17% owned CBS, 19% owned Yahoo!

Another week, another Met makes this list. Such is the way in Queens these days, where the team has been assembled with a lot of moving parts.

In our first edition of this column, we advised you to go out and grab Jose Valverde when Bobby Parnell was lost for the year. With the Mets having one of the worst collection of relief pitchers in baseball, Valverde looked to have a very good chance to keep the closing job, even if he struggled.

Well, Valverde has completely imploded to the tune of giving up six hits, including four long balls, and five runs in his last three innings of work. With three terrible outings in a row, and an ERA of 5.40, the Mets announced that Valverde would no longer be their closer.

Most speculation had the Mets going with a closer-by-committee system, until it was announced Sunday that the team would be giving Kyle Farnsworth, the only other Met reliever with success in the ninth inning, a shot at closing games.

That alone is enough to go out and grab Farnsworth, especially in NL-only leagues where the total number of closers is cut in half. The last time Farnsworth got a shot to close games for Tampa Bay in 2011, he saved a respectable 25 games in 31 chances with a 2.18 ERA and stuck out 51 batters in 57.2 innings. While those aren't Mariano Rivera numbers, the Mets would sign up for that in a heartbeat at this point. If Farnsworth can build off of his strong start this year, and come anywhere close to what he did as Tampa's closer in 2011, he's a lock to hold on to ninth inning duties as long as he remains in Queens. He needs to be owned immediately in all NL-only leagues.

Tom Koehler, Miami Marlins, SP

19% owned CBS, 3% owned Yahoo!

For many of the same reasons we like Henderson Alvarez, we like Tom Koehler. He pitches in a pitcher friendly park, is off to a solid start to 2014, and has little chance to lose his rotation spot barring a complete implosion.

Koehler has put together three quality starts to begin the season, and is the current owner of a 1.89 ERA and 1.11 WHIP. He only has one win to show for his efforts, and is not a strikeout pitcher (only 10 whiffs in 19 innings pitched), but he has an added benefit of getting two starts this coming week, against relatively favorable matchups on the road against the Braves and Mets.

Two start pitchers can be valuable as streaming options, but there is more than that at play here. If Koehler pitches well in his two starts this week, that will be five straight good pitching performances to start the year, meaning he'll end up on most astute fantasy owner's teams. In league specific formats quality pitching can get scarce quickly, so jumping on Koehler for this two start week to see if his hot start continues makes a lot of sense for owners with pitching woes.

Good luck in week four. Be sure to check out RotoBaller.com for anything you may need this fantasy baseball season. See you next week.