Fantasy Baseball Waiver Wire Adds: Week 13

Three outfielders lead a five-pack of must-add players as Week 13 begins.

There are just two weeks until the MLB takes a midseason break for the All-Star game, which will convene this year with baseball's brightest stars in Miami, Florida.

As we also continue nearing the midway point of the fantasy baseball season, it's important to keep your foot on the gas when it comes to either creating space in the standings, or making up as much ground as possible. With that in mind, here are five players who sit unowned in greater than 50% of leagues. Get 'em while you can.

Mike Fiers - Houston Astros (SP)

ESPN Percentage Owned: 48.3%

Simply looking at the season-long numbers of Mike Fiers would probably cause you to not even take a second look. Over 14 starts, his 4.46 SIERA doesn't necessarily jump off the page, but ignore Fiers at your own peril -- a closer examination reveals a hurler that's been a beast lately.

Fiers -- seemingly the only Houston Astros starter to not get hurt yet this year -- has progressively improved this season, and it's culminated with a brilliant June.

Over 25 1/3 innings pitched this month, he's posted a 1.42 ERA with a .241 wOBA and only a 20.3% hard-hit rate allowed.

If you've got the roster spot available, you can do much worse than Fiers when it comes to a middle-of-the-rotation kind of arm.

Mike Montgomery - Chicago Cubs (RP/SP)

ESPN Percentage Owned: 24.0%

Mike Montgomery didn't start the year in the rotation, but he's been given a shot to be a starter because of the injury to Kyle Hendricks. And he's making a strong case to stay.

He's posted a solid 3.23 FIP and 21.4% strikeout rate as a starter this year, compared to a mark of 3.87 and 17.6% as a reliever. Part of Montgomery's success is being driven by his ability to induce ground balls, which has settled in at a 63.3% rate as a member of the rotation.

The Chicago Cubs may turn back to Hendricks when healthy, but Montgomery has certainly been an effective short-term solution for both their rotation and fantasy staffs.

Shin-Soo Choo - Texas Rangers (OF)

ESPN Percentage Owned: 24.5%

The 2016 season was probably one that Shin-Soo Choo would like to forget. Choo suffered a ton of injuries -- including a fractured forearm -- and missed quite a bit of playing time, limiting him to only 210 plate appearances.

This year, however, has been a far different story.

He's already amassed 289 plate appearances and has been pretty effective, posting a .358 wOBA with 12 homers and 6 stolen bases. Perhaps most encouraging from his performance, though, is that Choo has improved each month, evidenced by a current .384 wOBA in June.

His 19.4% walk rate this month shows his refined batting eye remains, and his multi-category goodness should give make owners take notice if they're looking for outfield help.

Lonnie Chisenhall - Cleveland Indians (OF)

ESPN Percentage Owned: 11.8%

Lonnie Chisenhall has flown a little under the radar this season, and spending not one, but two separate stints on the disabled list doesn't help.

When he has been in on the fun, though, he is absolutely hammering baseballs. The outfielder is on pace for a career-best .288 ISO and .394 wOBA through 167 plate appearances, posting 10 jacks in limited playing time.

Chisenhall is just three homers away from his current single-season career-best mark, and playing home games at Progressive Field -- which ranks fourth in home run factor over the past three seasons -- should help keep him as a viable power option.

Tommy Pham - St. Louis Cardinals (OF)

ESPN Percentage Owned: 10.3%

One of the St. Louis Cardinals' best players this year didn't even begin with the major league club, starting the year in Triple-A and waiting for his time to shine.

Called up at the beginning of May, Tommy Pham has been absolutely crushing since getting promoted and should be entrenched in a role with Dexter Fowler now on the disabled list.

In 181 plate appearances, Pham's rocking a .359 wOBA and a .210 ISO, and what makes him particularly enticing is his power-speed combo -- he's already swiped 6 bags in the big leagues. Here's a glimpse of that power he's been displaying.

If you're in a pinch for a well-rounded outfielder or utility player, take a look at Pham.