Former SF Giants player we wish stayed: Kevin Gausman
Another obvious choice, but an important one nonetheless. Kevin Gausman, unlike Rodón didn't actually hit ace-level until he joined the Giants. The right-hander spent years bouncing around the league from the Orioles, Braves and Reds before landing in San Francisco in 2020.
After making 12 appearances of 3.62 ERA-ball in 2020, he went 14-6 with a 2.81 ERA and 147 ERA+ in 2021. In nearly every single facet, he broke out and became one of the best pitchers in the game.
Like so many before him, Gausman elected free agency and didn't return to the Giants after his time with the club was up. Instead, he signed a five-year, $110M contract with the Toronto Blue Jays. Since then, he has found a way to elevate his game even further.
Last year for the Blue Jays, Gausman, now 32, had a 3.35 ERA and American League-leading 2.38 FIP in 31 starts. He finished ninth in the Cy Young voting, but he did an exceptional job to prove that the year prior with the Giants was no fluke.
Naturally, his 2023 season is off to a red-hot start as well. In two starts, Gausman has a 0.00 ERA with 14 strikeouts in 12 innings of work. The Giants sure could use someone like him atop their rotation right now.