And most of the good vibrations felt toward Rodriguez centered on a pitch the Astros' projected No. 2 starter is planning to implement a lot more this season: the changeup.
Rodriguez, mainly a fastball-curveball guy over a stellar season in 2009, used his changeup often and effectively, especially on opposing right-handed hitters. And though he gave up a couple of runs on a pair of solo homers -- the result of two mistake, high fastballs -- he finished his outing surrendering just four hits while striking out seven and walking none.
"There's no doubt that he threw a lot better today than he has," said Astros manager Brad Mills, whose starter's spring ERA went from 12.60 to 9.00 after nine total innings. "And that's going to continue to get better. It's only his third outing, so it was nice to see him do that. That's how Wandy pitches, and he's going to continue to get better as we go."
Mills took extra satisfaction in pointing out that at least three of Rodriguez's strikeouts came on changeups, and he was able to even throw the pitch back-to-back on some occasions.
That's a big improvement from last year, when Rodriguez was the Astros' best starter with a 3.02 ERA but was pretty much a two-pitch guy.
"We didn't use it much [last year] because it wasn't sinking, so I didn't call for it as much," Rodriguez's catcher on this afternoon, Humberto Quintero, said in Spanish. "I asked for the curveball instead. But now that it's sinking, we're going to use it more during the season."
Rodriguez's changeup has the type of sinking action of a two-seamer, and he's able to throw it in the 78-80-mph range to offset a low-90s fastball and a wicked curveball -- his money pitch.
New Astros pitching coach Brad Arnsberg estimated about 15-18 of Rodriguez's 70 pitches were changeups, with most of them coming in his last two innings of work.
"He was pretty much fastball -- two-seam, four-seam -- and hook, and he featured that changeup [last year]," Arnsberg said. "But he's in the process of trying to throw it again for strikes and in counts that dictate, 'I need a swing here,' and then other counts where, 'I want a swing out of the zone.'
"There were times even today where I think the hitters might have been sitting on [the changeup], and it's still ducking the zone. He's got nice life to it."
Arnsberg pointed out that on top of giving opposing hitters something else to think about: Effectively using a changeup can extend careers.
"Even the veteran guys that have worked around here, I've tried to teach them, 'Learn it now, because you're not always going to be 93, 94 [mph on your fastball],'" Arnsberg said. "Of course, Wandy doesn't have that kind of velocity, but you're not always going to have that kind of arm strength. So why not learn it now? And when, three or four years from now, when you're 90, 91, you don't have to go searching for it at that time. Get a good feel for it now, and it will pay big dividends down the road."
Coming off losing his arbitration case to the Astros in February -- settling on $5 million instead of the $7 million he requested -- Rodriguez gave up three runs in two innings in his Grapefruit League opener against the Tigers on March 5.
Then, exactly one week ago, Rodriguez was charged with six runs (four earned) on six hits in a three-inning effort against the Marlins.
Despite the vast improvement on Wednesday, Rodriguez said he's "not ready right now" for the start of the season and needs at least two more starts to feel like he's good to go.
But at least Wednesday's was a step in the right direction.
"I felt better today, and I worked a lot on all my pitches and used [them]," Rodriguez said. "I had a good one."
Alden Gonzalez is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.