Whenever any phenom prospect comes up to the majors, there’s just as much of a chance of him taking MLB by storm as there is of him struggling to adjust to the major leagues. In his rookie season, Grayson Rodriguez managed to embody both of those extremes as he put together two polar opposite stretches of pitching.

Rodriguez came into the 2023 season as a consensus top 10 prospect in all of baseball for the second year running. After suffering a right lat strain in 2022 that cost him two months of the season and a chance at a major league call up, G-Rod entered spring training with every chance to pitch himself into the major league rotation. However, a shaky performance in the spring meant that Rodriguez once again started the year at Norfolk, waiting for injury or poor performance to open a spot in Baltimore’s rotation.

His wait ended up being a lot shorter than any could’ve expected. When Kyle Bradish took a line drive off his foot in his first start of the season, it suddenly meant that the Orioles had an opening for a starter in the major leagues. And so Mike Elias summoned Rodriguez, after only one start with the Tides, to make his MLB debut in his home state of Texas.

The rookie’s debut against the Rangers got off to a rocky start, but ultimately gave the Orioles a good glimpse at his abilities against major league opposition. Pitching in front of a packed family and friends section, perhaps the nerves got the better of G-Rod at first. He walked the first batter he faced and gave up a two-out double and single to give the Rangers a 2-0 lead after one. However, the rookie flamethrower settled in quickly after that unfortunate first inning, pitching four scoreless innings and punctuating his final frame with a strikeout of Corey Seager.

That first start for Rodriguez proved to be a nice allegory for his rookie season as a whole. Which is to say, the rest of the beginning of his inaugural campaign was rough. After a strong showing in Texas, his next two outings were rocky—allowing five runs over 4.1 innings in his Camden Yards debut vs. Oakland and following that up with four runs allowed in five innings against the White Sox. Thanks to back-to-back scoreless starts against Detroit, Rodriguez finished his first month in the big leagues with a 4.07 ERA, a 2.89 FIP and 34 Ks in 24.1 innings.

However, after a mostly promising first month, things would get a lot worse before they got back on track. No matter how you slice it, May was Rodriguez’s worst month of the season. He started off with a clunker, allowing six runs off three home runs in 3.2 innings against the lowly Royals. He rebounded nicely, posting 5.2 innings of two-run ball to score a win against the Rays, but he could not replicate that success. Over his next three starts against the Angels, Blue Jays and Rangers, Rodriguez allowed 19 runs, six home runs and opponents were hitting .364 with a .800 slugging percentage.

Much of G-Rod’s struggles early on came down to an inability to keep hitters from teeing off on his fastball. In May alone, opponents hit .500 with a 1.048 slugging percentage of Rodriguez’ heater. When your whole plan as a young pitcher is to get ahead with your upper-90’s fastball—and then work your slider and changeup off of that—hitters dominating your fastball will always prove disastrous. His disastrous start against the Rangers proved to be the final straw on Rodriguez’s first act, as the Orioles optioned him back to Norfolk on May 27.

Evidently, this demotion back to Norfolk was exactly what Rodriguez needed to get back to his normally-dominant self. In seven starts for the Tides between June 3 and July 9, Rodriguez posted a 1.69 ERA, .171 BAA and punched out 54 over 37.1 innings. That was more than enough to earn him his second call-up of the season, and he returned to the Orioles on July 17.

If you only saw Rodriguez pitch in the majors from July onward, you would’ve never known that the 23-year-old had ever struggled against MLB hitters. In his first start back he allowed four runs over five innings against the Dodgers. That was the last time he allowed four earned runs in a start the rest of the regular season. In G-Rod’s first seven starts back in the bigs he faced the Dodgers, Rays, Yankees, Astros, Padres and the Blue Jays twice. In those seven starts against some of the best lineups in the majors, he posted a 3.24 ERA, a .218 BAA and limited opposing hitters to a .577 OPS—and from there he got even better.

Throughout the second half as a whole, Rodriguez was one of the best starters in the American League. In 13 starts across July, August and September, the rookie had a 2.58 ERA, a .227 BAA and punched out 73 batters in 76.2 innings. After allowing three home runs apiece in May starts against the Royals and the Rangers, he allowed only three home runs total across all of his starts in the second half. While his second half numbers didn’t quite live up to Cy Young winner Gerrit Cole or teammate Kyle Bradish, Rodriguez bested other Cy Young finalists Sonny Gray and Kevin Gausman with his performance from July onward.

His crowning achievement came in his final start of the season against Tampa Bay. After losing the first two games of a pivotal series with the Rays, the Orioles were in a virtual tie atop the AL East and had their backs against the wall. Rodriguez responded with his best start of the season, throwing eight scoreless innings with seven Ks in a 8-0 O’s win.