The right-handed pitcher from Defiance, Ohio, had a 5-0 record and 1.31 ERA in 13 appearances last season, striking out 58 in 48 innings.
But on April 21, Kidston left a game against St. John's after seven strong innings with some arm trouble. He spent two weeks trying to rehab the injury to get back in time for the Big East Tournament and U of L's postseason run.
"But then I felt a little more pain," Kidston said. "They did another MRI and this time they did the one with dye and that's when I found out that I tore my labrum."
Kidston, who was later named a Louisville Slugger Freshman All-American, missed the rest of the season. His long rehab ended on Tuesday when Kidston took the mound for the first time this season for Louisville, pitching three strong innings and picking up a win as U of L downed Western Illinois 9-0.
"It's been a long recovery process and a little harder than I thought it was going to be," Kidston said. "It's been an experience that I hope I never have to go through again, but I made it back and I feel good.
"There was a little rust but I'm OK."
Kidston pitched three innings, allowed one hit and walked two while striking out four.
"It was great to see him back out there," U of L coach Dan McDonnell said. "That's a big boost for our pitching staff."
As a freshman, Kidston was a standout on a strong staff and he could push for a spot in the weekend rotation with a few more appearances.
U of L pitching coach Roger Williams limited Kidston to 52 pitches on Tuesday and he will likely see a mid-week start again next week.
"It was hard to sit out and watch," Kidston said. "But I just thank the Lord that I am back in this position. It's been a long road.
"I have been throwing for about five months now but hit a little bump a month ago and shut down for about 10 day. I went (to the Dr.) and he said the arm was ready to go, so he said when I was ready to go that it was fine. I felt so good after the first (simulated game) that I told coach Williams I just wanted to go.
"I'm pretty fired up."
BIG WEEKEND SERIES
U of L (12-4) will host a big three-game series this weekend with Southern Conference for Samford (11-5) at Jim Patterson Stadium.
The games will be played at 3 p.m. on Friday and 1 o'clock on Saturday and Sunday.