Week 4 Fantasy Baseball Waiver Wire: 5 Arms To Add Immediately

McAllister has enjoyed a brilliant start to the 2014 season. The right-hander currently owns a 2.28 ERA and he has won three consecutive starts. He also has yet to yield a long ball. The 26-year-old is in the middle of a breakout fantasy campaign and deserves a little credit for it.

Ownership: 16.2% (ESPN)

Hammel has a 3-1 record right now and he currently owns a glimmering 2.60 ERA with a 0.69 WHIP. The right-hander continues to go deep into his starts and the veteran is averaging 101.8 pitches per start. He won't be in Cy Young contention, but he will be one of the best situational starters to utilize down the stretch this season.

Ownership: 26.8% (ESPN)

Mejia, 3-0, has been one of the biggest breakouts candidates of the young fantasy season. The 24-year-old is holding opposing hitters to a meager .193 batting average and his 1.99 ERA is simply stunning. Mejia has also struck out 25 batters through 22.2 innings of work and he continuously attacks the lower half of the strike zone. He is a must-own right now in all formats.

Ownership: 10.6% (ESPN)

Simon has been a pleasant surprise within Cincinnati’s rotation this season. He has a 2-1 record with a sub-1.00 ERA (0.86) and the 32-year-old has lasted an average of seven innings in each start. He won’t be this untouchable all year long, but he will do enough to be a decent flex starter the rest of the way.

Ownership: 45.2% (ESPN)

Perez is coming off back-to-back complete game shutouts in which struck out 11 and allowed only 12 total bases runners (7 H/5 BB). Unfortunately, he is still not receiving much attention. The 23-year-old has quickly transitioned to the majors and his 1.42 ERA is among the tops in fantasy. Add this Venezuelan fireballer immediately, before he officially becomes the next Johan Santana.

Ownership: 77.9% (ESPN)