If history has taught us something is that you cannot perform at the highest level unless you have some stellar pitching. Even some MLB teams that struggle to get hits have won the World Series thanks to their aces on the mound.

It doesn't matter how many runs you can put up or how good your defense is. The sad and hard truth is that no team can win unless it has some solid and reliable arms in the rotation and the bullpen.

Nonetheless, for whatever reason, some of the best hurlers in Major League Baseball remain unsigned this deep into the offseason. That's why today, we're going to make a case for the best pitchers still available.

MLB News: The Best Pitchers Still Available

3. Zack Greinke

Zack Greinke - Getty Images

Zack Greinke - Getty Images

Even though he's coming off a down year by his standards, the fact that Zack Greinke is still unsigned at this point in the winter is mind-boggling, to say the least. Especially considering he may not need a lot of money to join a contender.

Greinke has been one of the most consistent and steady contributors on the mound over the past decade or so. He's better than most team's fourth starter at the very least, so he should've gotten more interest in free agency.

2. Aroldis Chapman

Aroldis Chapman - Getty Images

Aroldis Chapman - Getty Images

It seemed like the Aroldis Chapman era with the New York Yankees was all but over. And now that Brian Cashman has yet to re-sign the Cuban Missile after all the deals they got done, that might as well be the case.

Chapman has struggled with control and consistency as of late, and some believe his days as a closer are numbered. But he's still one of the best RPs of the past two decades and should get another shot to prove his worth.

1. Nathan Eovaldi

Nathan Eovaldi - Getty Images

Nathan Eovaldi - Getty Images

Once again, Nathan Eovaldi was one of the few — if not the only — bright spots for the Boston Red Sox last season. He was efficient, consistent, and helped them stay in games even when their offense couldn't get the job done.

But, considering how Chaim Bloom has handled his payroll over the past couple of years, a return to Fenway Park just doesn't seem realistic at this point. Needless to say, multiple teams could and should be interested in his services.