Nick Mariano's starting pitcher (SP) fantasy baseball waiver wire adds. Pickups and starting pitcher sleepers for Week 4 of the 2017 MLB season.

It’s been quite the wild ride through the first three weeks of the 2017 season. While we don’t want to be overreacting here, it’s never a bad time to check up on the waiver wire and see which under-owned arms might be available to help your squad.

For our purposes, we’re going to use Yahoo ownership levels and try to cut things off around 35%. Data accurate as of April 25.

Let's get to it.

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Starting Pitcher Waiver Wire Targets

Robert Gsellman - (NYM, SP): 26% owned

Gsellman will be skipped in the rotation after his start on April 25 was rained out, which was done in order to keep Noah Syndergaard on schedule. That means Gsellman may make a bullpen appearance, so set your roster accordingly if you do or don’t want accidental bullpen stats from the starter. Since last week’s post, he went out and dominated the Phillies over seven strong innings, but couldn’t get a win with his first quality start of 2017.

He now has a lovely 10.19 K/9 with a 3.48 FIP, 3.02 xFIP and 3.10 SIERA, though his 7.5 percent swinging-strike rate really doesn’t point to a K-heavy arm. It was 9.1 percent last season when he posted an 8.46 K/9, for a small reference point. He’ll likely face the Nationals in Washington in his next start.

Hector Santiago - (MIN, SP): 22% owned

Santiago improved to 2-1 after a six-strikeout quality start against the Tigers at home on April 21, as the southpaw now sports a 2.19 ERA and 0.97 WHIP through four outings in 2017. His 4.16 SIERA is nearly double the ERA, of course, but his 10.1 percent swinging-strike rate is a career-high mark and he’s always been a low-BABIP arm. His .247 mark comes after respective rates of .252 and .260 in his last two seasons. His control will be the X-factor, as his current four percent walk rate is way down from 10.1 percent last season. Keep an eye on that when he goes to Texas to face the Rangers on April 26.

Miguel Gonzalez - (CWS, SP): 18% owned

Gonzalez was an above-average arm last season, posting a 3.73 ERA and 1.24 WHIP that were mostly just separated from extraordinary levels by a couple of terrible outings. There’s certainly something to be said for consistency and a guy who can avoid the bombshell start, but he’s picked up right where he left off this season with more of those above-average trips to the hill.

While we all know the 2.00 ERA and 1.07 WHIP are over his head, the 3.29 FIP is a fan of his being more aggressive in the zone. The percentage of pitches in the zone for Gonzalez went from 41.7 percent to 44.7 percent last season, and is currently 45.4 percent in 2017. He’ll look to remain strong in Detroit against the Tigers on April 30.

Zack Wheeler - (NYM, SP): 21% owned

Wheeler’s 5.40 ERA may be holding him back from being truly recognized as a potential breakout arm this season, but despite an innings cap looming he has shown signs of being plenty useful in 2017. Not only does he have 21 strikeouts in 21 2/3 innings (who doesn’t like a strikeout per inning?) but his FIP (3.75), xFIP (3.59) and SIERA (3.48) all point to mid-threes arm who has pitched better than the results indicate. If his ERA was currently even just 3.90, how high would ownership be?

Dan Straily - (MIA, SP): 16% owned

Straily kicked in the doors to the waiver-wire conversation by following up his 5 1/3-inning no-hit bid on April 16 with 14 strikeouts against the free-swinging Padres on April 22. He won’t face the Pads every time, but this is an arm that now has a 3.25 ERA and an 8.62 K/9 dating back to 2016’s All-Star break. The 1.71 HR/9 rate in that span is rough, but even just getting that down to his career 1.39 mark would make a difference. He’s been more than just a short-term splash is the point here.

Patrick Corbin - (ARI, SP): 13% owned

Corbin still has a bloated 1.45 WHIP, but brought his ERA down to 3.10 after allowing only two runs over seven solid innings alongside nine strikeouts against the Padres at home on Tuesday. He’s now 2-3 on the season, but the southpaw has now posted back-to-back quality starts with at least eight Ks -- it’s just both of those came against San Diego. He’ll face the Rockies in a tougher home matchup on April 30 next, so this is just a more general awareness-raiser rather than “pick him up and start him right now” blurb. His 3.67 FIP, 4.04 xFIP and 4.08 SIERA like what he’s doing, though, for the record.

Charlie Morton - (HOU, SP): 10% owned

Morton hasn’t exactly delivered on that preseason buzz with a 4.29 ERA and gaudy 1.57 WHIP, but he does have 19 strikeouts in 21 innings and is fighting through a career-worst .353 BABIP to become valuable for fantasy owners again. He gets to face Oakland next, where he’ll look to show why he has a 3.15 FIP, 3.92 xFIP and 3.97 SIERA alongside the solid strikeouts.

Jesse Hahn - (OAK, SP): 7% owned

Hahn appears to have rebounded from an ugly 2016 campaign (6.02 ERA, 1.64 WHIP) and recaptured his old form from ’14 and ’15 as he currently has a sparking 2.05 ERA that houses a 2.94 FIP within it. His Tuesday start yielded eight innings of shutout ball in which he only allowed one hit and two walks with six strikeouts, making him a big pickup.

While his 3.99 xFIP doesn’t like him as much, he has posted HR/9 marks of 0.49 and 0.47 in ’14 and ’15, respectively, so I’d buy the FIP over xFIP here (current 0.35 HR/9). His 4.15 SIERA likely doesn’t buy the .205 BABIP (totally fair), but his respective rates in those two previous seasons were .270 and .273. He has the command to create his own luck and be of use to fantasy owners here.

Trevor Cahill - (SD, SP/RP): 4% owned

In case you missed it, Cahill regained his formed out of the bullpen for the Cubbies last season with a 2.74 ERA, 1.28 WHIP and 66 strikeouts in 65 2/3 innings (one spot start). While his peripherals weren’t strong, his grounder-heavy arsenal was perfect for a historically great defense behind him. The Padres can’t provide him the same caliber of glove behind him so I expect his .233 BABIP to rise beyond his ’16 mark of .246, but he’s made up for that by pitching better.

His 3.35 FIP, 2.90 xFIP and 3.03 SIERA are all better than his 3.44 ERA and his 14.8 percent swinging-strike rate points to a guy who should keep his strikeout-per-inning stuff from last season when that rate stood at 11 percent. The wins may not flow in, but why he’s owned in fewer leagues than Clayton Richards boggles my mind.

Jesse Chavez - (LAA, SP/RP): 2% owned

Chavez was misused out of the bullpen in 2016 and had a rough season as a result (4.43 ERA, 1.33 WHIP), but has posted a 3.13 ERA as a starter thus far in 2017 with a .238/.312/.398 triple slash against. He’s not getting lucky and needs to work on inducing poorer contact, but I guarantee if his ERA was a full run lower (aka, if he didn’t need to pitch out of the ‘pen in an extra-inning game) alongside the 8.63 K/9 then his ownership would be at least five percent or so.

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