Valverde hit .217 with the Eugene Emeralds last year over 40 games, with eight doubles, two homers and 24 RBIs.
Corbeil was signed as a street free agent signed roughly a month ago but never made it into a professional game with the Padres.
Fernandez, traded to the San Francisco Giants for Michael Wagner, was returned to the Padres after failing a physical. He was released because his fastball, which normally sat in the mid to upper-nineties, had dropped to the high-80s.
Fernandez went 10-17 over his career with the Padres with a 4.35 ERA in 240 innings of work. The Padres checked his arm for trouble but could not find any injury - thus the release because of the drastic dip in velocuty.
Colt Morton, Brett Bonvechio, and Bobby Basham are getting close to returning. Morton has been taking swings off live pitching and been squatting behind the dish. Bonvechio has also been taking hacks. Basham has been throwing sideline sessions over the last two weeks and will be tossed into the fire shortly.
On the signing front, Kellen Kulbacki has yet to sign but things will get underway soon.
"The negotiation process starts on Tuesday," Kulbacki said. "A scout will be coming to my house."
There should be little hangups in the negotiations to sign the former James Madison mauler. He will report to camp in Eugene once he signs.
The Emeralds will begin workouts on Wednesday and several players have already been signed. A full list will be available soon.