An 11th-round Draft pick out of Rice in 2013, Simms, 23, has yet to allow more than one run in any of his five outings (four starts) for the Rafters, posting a 1.71 ERA with 16 strikeouts over 21 innings in that span.
"My defense has been great behind me," Simms said when asked about his successful Fall League campaign. "Those guys have made a ton of great plays, especially on some double-play balls. They've definitely helped me get out of a few jams and pitch deeper into starts."
While Simms' fastball tops out at only 90-91 mph, he keeps hitters off balance by effectively mixing his pitches and working both sides of the plate. Specifically, Simms' feel for his changeup has stood out this fall along with his willingness to deploy it against both right- and left-handed hitters.
"I actually went back to the grip I used in college late in the season," said the 6-foot-3, 205-pound right-hander. "I finally started to feel comfortable throwing the pitch when I wanted to, and it's never felt better coming out of my hand than it has out here."
Meanwhile, Simms' success in the AFL carries extra significance after he underwent offseason hip surgery and then missed most of April working his way back in extended spring training.
"I basically had to relearn how to use my lower half when I pitched. It was a long road back with the surgery and rehab, but I just took it one day at a time and eventually got back to where I needed to be," he said.
After he returned to action, Simms spent a majority of the season at Class A Advanced Potomac of the Carolina League, where he posted a 2.74 ERA and held opposing hitters to a .219 average over 88 2/3 innings (14 starts).
Simms was promoted to Double-A Harrisburg -- where he finished his 2014 campaign -- in late July and ultimately made eight starts for the Senators, posting a 4.40 ERA in 45 innings. Between both stops, Simms registered a 3.30 ERA and established new career highs with 22 starts and 133 2/3 innings pitched.
With his start Tuesday, Simms now ranks among the AFL leaders in ERA, strikeouts and innings pitched.
Salt River scored first in the contest as catcher Oscar Hernandez's two-out single to center field plated Blue Jays outfielder Emilio Guerrero, who had walked and reached third on an error by Peoria starting pitcher Ryan Butler.
Butler, the Padres' No. 11 prospect, struggled with his control in the outing, allowing four hits and two walks in three innings, but ultimately yielded just one run, lowering his Fall League ERA to 1.50 through 12 innings.
Meanwhile, Padres No. 15 prospect Fernando Perez's solo home run in the fifth inning against Simms accounted for the Javelinas' lone run in the contest.
The Rafters took the lead for good in the top of the eighth inning, when Mets second baseman L.J. Mazzilli and Twins outfielder Daniel Palka delivered back-to-back doubles with two outs to break the tie.
Chad Girodo -- who opened eyes during Saturday's AFL Fall Stars Game -- nailed down the ninth inning for Salt River to earn his first save of the Fall League. The Blue Jays' lefty has yet to allow an earned run through eight innings for the Rafters.