Francisco Liriano spent last summer rehabbing his reconstructed elbow. He’ll spend this summer reinventing himself as a pitcher.

His three starts in the major leagues this month were a harsh, if necessary, lesson. The Liriano of 2006 is gone, kaput.

It isn’t just the effects of his ligament-replacement surgery. It’s the new, less violent, more conventional delivery; it’s the decision to de-emphasize the slider.

Broadcasters keep saying he needs to “regain” command of the fastball. That’s the wrong verb. He never had command of the fastball. Didn’t before 2006 (that’s what kept him in the minors in 2005); didn’t during 2006.

This column detailed Liriano’s pitches and results after Liriano’s 2006 matchup with Roger Clemens.

In that game, the Astros almost never swung at a pitch 90 mph or above unless there were two strikes. And Liriano threw balls with about half those pitches.

He dominated despite that. He dominated because his slider was so good that even when he fell behind with his fastball he still overwhelmed even good major league hitters.

That isn’t supposed to happen, at least not with starting pitchers, and in fact it was unsustainable. Between the stressful delivery and 40 or so sliders a start, Liriano’s elbow was doomed.

Today Liriano’s fastball velocity is roughly the equivalent of Brad Radke’s at his peak. That’s plenty good enough — Radke certainly had a distinguished career — but Liriano not only lacks Radke’s command, he lacks Livan Hernandez’s command, and Hernandez walks 80-plus batters every year.

There are basically three paths for Liriano to follow:

1. Reinvent himself as a conventional pitcher. A tough chore, considering how unconventional he was to begin with.

2. Return to the old delivery and approach — throwing 40 percent sliders — and hope the elbow holds up. Not likely.

3. Shift to the bullpen with the old delivery. Mike Jackson and Larry Anderson had long careers as relievers throwing almost nothing but sliders. Again, however, there’s no guarantee that Liriano’s elbow will tolerate the old delivery, even for 20 pitches a game rather than 100, and especially for 60-plus games a year rather than 30-plus.

The Twins have been understandably reluctant to consider the bullpen option for Liriano. A top-grade starting pitcher is more valuable than any reliever.

It makes sense for the organization to keep him as a starter for now. Maybe the velocity will return; maybe the new delivery will enhance his command as it becomes more routine for him. Maybe.