Ervin Santana crashed to earth on Sunday, giving up six runs in his first poor outing of 2017. His bad day doesn't change his future. For the next few months he'll be the subject of trade rumors.

It's May 8, yet you've probably heard the argument 100 times: The Twins must trade Santana to acquire good young pitching.

This sounds perfectly logical if you ignore, you know, the facts.

Santana is 34. He is signed for 2018. The Twins have an option to keep him for 2019.

It seems the people who most want to see Santana traded are the same ones who will complain if the Twins continue to fail, and if Santana is traded for less-expensive players, and if the team tries to sell another rebuild with another wave of young players.

The perfect summer scenario for the Twins would be Santana keeping them relevant until July 31, then being traded for a top pitching prospect who will transform the franchise. In reality, both of those eventualities are far-fetched.

Trades sound great before they're made, but we tend to glorify the good ones and forget about the bad ones. There is no guarantee and there may not even be a likelihood that trading Santana will bring back a pitcher who can perform like Santana.

The winter after he hit 42 home runs as a second baseman, Brian Dozier would have brought only one good pitching prospect in return. The Twins were right not to trade him for that, and they would be right not to trade Santana merely for whatever the market will offer.

The success of the Twins' rebuild depends on amassing pitching depth, and finding some excellence along the way. Kyle Gibson's collapse and Adalberto Mejia's disappointing start to this season, in the majors and at Class AAA, have the Twins giving Nick Tepesch a second start on Thursday and probably calling up Jose Berrios for Saturday.

Let's repeat that, with emphasis: The Twins are above .500, and they are giving Nick Tepesch a second start. These facts cannot coexist for long.

The Twins traded Denard Span and Ben Revere to add starting pitching. They wound up with Alex Meyer, Trevor May and Vance Worley.

When they traded Johan Santana, they wound up with outfielder Carlos Gomez. The pitchers they received in that deal were Philip Humber, Kevin Mulvey and Deolis Guerra.

For all of their activity in the trade market over the years, the Twins haven't traded for a young pitcher who would rise to the top of their rotation since they traded for Francisco Liriano and Carlos Silva in 2003.

More recently, they traded the Mickey Mantle impersonator Aaron Hicks for John Ryan Murphy, who apparently was immediately placed in the witness protection program and is working at the Giggle Springs Convenience Store in Tonopah, Nev.

Santana is a professional who doesn't depend on velocity or a violent motion to get outs. The only major flaw on his résumé was his suspension for using a performance-enhancing substance in 2015. That was egregious, but it is not likely to be repeated. This should become the fifth consecutive season in which Santana's ERA is at 4.00 or better.

"Most of the things he does in terms of being a veteran are quiet," Twins manager Paul Molitor said. "But I know there's influence there. You hear people talk about it. Jose [Berrios] shouldered up to him throughout the spring. I think his consistent demeanor is something that the guys pick up on.

"He showed a little emotion today on the mound. That's a little uncharacteristic. But he's in a little different spot. He's a top-of-rotation guy on a team where he's come out and had an outstanding start. When he pitches, we seem to be a different team. That reflects on who he is."

Unless another team offers a young ace, the Twins should be happy to keep Santana, and other teams are very unlikely to offer a young ace. The Twins should love the one they're with.

Jim Souhan's podcast can be heard at MalePatternPodcasts.com. On Twitter: @SouhanStrib. jsouhan@startribune.com