Fantasy Baseball Waiver Wire Adds: Week 18

Are the Rangers finally going to see if Joey Gallo can sink or swim?

You can count on one hand the number of players in baseball who have the kind of power Texas' Joey Gallo possesses.

Miami's Giancarlo Stanton is perhaps the only one who can beat Gallo's pure power, and in the few instances in which Gallo has been given a chance to display that awesome power on the Major League stage, it's been breathtaking to watch.

I mean, look at what he did to this poor baseball thrown by none other than the great Clayton Kershaw last year.

Yowza. However, Gallo has also been maddeningly inconsistent in his 139 career plate appearances, hitting .187/.281/.398 with a strikeout rate of 47.5% and a wRC+ of 75.

You simply can't strike out in nearly half of your plate appearances and expect to stick around in the big leagues, something Gallo has tried to learn without a lot of success in the minors. He will almost never be capable of keeping his strikeout rate under 30%, but if he can at least hit like he did in AAA this year (.246/.381/.557 with 19 homers and a 17.7% walk rate in 299 plate appearances), then he will be a very valuable player, both for the Texas Rangers and in fantasy for the rest of the season.

If you're in a dynasty league, he's a no-doubt add this week, owed in just 17.3% of all ESPN leagues.

He could be the game's next great power hitter. Or, he could be the game's next great offensive black hole. He's worth the risk if you have the roster space.

Aaron Altherr - Philadelphia Phillies (OF)

ESPN Percentage Owned: 7.0%

Philadelphia's Aaron Altherr doesn't have the power potential that Gallo has, but he has the potential to be an all-around valuable offensive player. And he'll certainly get the plate appearances this year to prove he's a big-time Major Leaguer.

In just 39 games last year (161 plate appearances), Altherr finished second on the 2015 Phillies in fWAR (1.7). That's insane. He batted .241/.338/.489 with 5 homers and a wRC+ of 124, darn good production in just over a month of action.

He would have been the Phils' starting left fielder this year, but a wrist injury in spring training knocked him out of action until last week. And in his first game back against the Atlanta Braves on Friday, Altherr went yard.

Altherr has stolen base ability as well, so he's certainly worth a pick-up.

Tyler Skaggs - Los Angeles Angels (P)

ESPN Percentage Owned: 31.4%

Yo, Tommy John surgery sucks, man.

After missing all of last year and about two-thirds of this season, Angels starter Tyler Skaggs is finally healthy and throwing on a Major League mound again.

The 25-year-old left-hander is off to a great start in his big league return. He has yet to give up a run in 12 1/3 innings of work, averaging more than a strikeout per inning in two starts thus far. And with a hook like this, it's easy to see why.

Skaggs has one full season as a big league starter under his belt, two seasons ago, when he was 23. He went 5-5 in 18 starts with a 4.30 ERA and a 3.55 fielding independent pitching (FIP), averaging 6.85 strikeouts and 2.39 walks per nine innings.

David Dahl - Colorado Rockies (OF)

ESPN Percentage Owned: 32.7%

Hey, so remember at the start of the season when the Colorado Rockies were supposed to be very bad and players such as Carlos Gonzalez and Charlie Blackmon were supposed to be traded at this year's trade deadline? Yeah, not so much.

Entering Monday, the Rockies were just a game under .500 and reasonably still within shouting distance for the second National League wild card, five games out. Joining the party is young outfielder David Dahl, who has begun contributing right away, hitting .370/.393/.630 in 28 plate appearances with 2 jacks already.

Dahl's minor league numbers this year were outstanding. He hit .484/.529/.887 with 5 dingers in 68 AAA plate appearances and .278/.367/.500 with 13 homers in 332 AA plate appearances this season. He also stole 38 bases in those two stops combined.

So you've got a pretty terrific speed-power combo guy, albeit one who doesn't take a base on balls all that often and strikes out a bunch. But he's certainly a fantasy relevant player for the rest of this season.

Tony Watson - Pittsburgh Pirates (RP)

ESPN Percentage Owned: 26.9%

So the Pittsburgh Pirates traded their closer, Mark Melancon, this week.

It was an interesting move for the Pirates, who are four games out of the second wild card spot entering play Monday. But they wouldn't have done it if they didn't think they had someone capable of closing games out, and the pitcher who will get the first opportunity to take over the reins is Tony Watson.

It's not all that often you get a new closer opportunity for a potential playoff contender at this stage of the season, so Watson will no doubt be a popular pick-up this week. The 31-year-old has been a solid bullpen arm for the Pirates for years and is 1-3 with a 2.64 ERA and a 3.70 FIP, averaging 7.92 strikeouts and 3.05 walks per nine innings.

Watson was even better the last two seasons with a 1.91 ERA last year and a 1.63 ERA the season before.

Braden Shipley - Arizona Diamondbacks (SP)

ESPN Percentage Owned: 4.6%

If you're in a deep league or an National League-only league, Braden Shipley is worth stashing on your roster.

Arizona's top pitching prospect has been called up to the Majors, and in two starts so far (11 1/3 innings), he has an ERA of 4.76 and a FIP of 6.49. In 19 AAA starts he posted a 3.70 ERA and a 3.80 FIP, averaging 5.81 strikeouts and 1.66 walks per nine innings.

Clearly, he's not a big strikeout guy. His job is to get batters to put the ball on the ground, which he has done in his two starts, at 51.4%.

He won't win you your title this year, but he might be able to help you get over some rough spots if he can pitch like he has in his minor league career