Ah, the No. 1 pitcher. The "ace" of the staff. The guy your team sends out there every fifth day expecting a win. We know those arms, especially to start off this year: Max Scherzer, Justin Verlander, Zack Greinke, among others.

However, there are some "aces" that are failing to live up to their status as an elite starting pitcher.

Here are six pitchers who should turn in their "Ace" card.

6. Kyle Freeland

Baltimore Orioles v Colorado Rockies

Kyle Freeland had a breakout season in 2018 with the Colorado Rockies. Finishing fourth in the NL Cy Young race, Freeland earned the Opening Day nod for Colorado. But ever since he's been a disaster. Through 12 starts, he's posted a 2-6 record and a concerning 7.13 ERA, causing him to be sent down to Triple-A. A lot has certainly changed in a year for Freeland.

5. Yu Darvish

Chicago Cubs v Washington Nationals

Yu Darvish is no longer the dominant ace like we've seen during his days with the Texas Rangers. Despite struggling in the 2017 World Series for the Los Angeles Dodgers, the Chicago Cubs threw $126 million his way, and he's simply not lived up to the lucrative contract. His 4.95 and 4.88 ERA's through his first two seasons in Chicago are evidence of that.

4. Rick Porcello

Seattle Mariners v Boston Red Sox

Rick Porcello was the apple of the Boston Red Sox's eye back in 2015 when they acquired him from the Detroit Tigers for Yoenis Cespedes. Meant to be the next ace for Boston, Porcello has been wildly inconsistent throughout his tenure. In 2019, he has a 4.86 ERA and has been a main contributor to Boston's pitching woes. That doesn't sound like the 2016 Cy Young winner.

3. Chris Archer

Pittsburgh Pirates v Arizona Diamondbacks

Chris Archer was viewed as the next great ace for the Tampa Bay Rays. Once the team decided to hit the reset button, the Pittsburgh Pirates came calling, as they sent top prospects Tyler Glasnow and Austin Meadows to finalize the trade. This season with the Pirates, Archer is struggling (5.20 ERA), but signs were evident before this year. He hasn't had under a 4.00 ERA since 2015.

2. Corey Kluber

Atlanta Braves v Cleveland Indians - Game One

This one might be a bit controversial, but his start to this season suggests his decline could be in order. Before going down with a broken forearm, Kluber was 2-3 with a 5.80 ERA and 1.65 WHIP in seven starts. And can you really be considered an ace when your last four postseason starts (including Game 7 of the 2016 World Series) have resulted in an 0-2 record (1-3 for the team) and 10.20 ERA?

1. Madison Bumgarner

San Francisco Giants v New York Mets

Like Kluber, there's no question Bumgarner has the tools to return to ace status. However, MadBum just simply hasn't been the guy we're all accustomed to seeing shutting down the opposition. After his sensational 2016 season, the left-hander owns a terrible 13-22 record with a 3.43 ERA. Sure, that ERA isn't bad at all, but that's not No. 1 pitcher-type stuff. He's no longer unhittable and it's clearly shown over the past two-plus years.