"I came in here sprinting today," said the 39-year-old veteran, who was scheduled to play later in the afternoon to make sure everything was OK.
Percival said the plan for now is to receive a second epidural -- with six days in between injections -- although a third round could be used depending on how his back feels.
Percival -- who has also been hampered by cartilage damage in his right knee -- will have to undergo back surgery when the season is over, but was game for trying "whatever works" to get back to his early-season form.
The Rays are 34-1 when Percival enters the game in a save situation, but the right-hander has struggled since coming off the disabled list (right knee) on Sept. 1. In his past four appearances, Percival has allowed four walks and five hits -- two of which were home runs -- totaling seven runs.
If a save situation arises in Thursday's series opener with the Twins, the Rays will go with setup man Dan Wheeler, who received the bulk of the closing duties when Percival was on the DL.
The club will also have David Price available out of the bullpen if necessary on Thursday night, as the young starter-turned-reliever last tossed 5 1/3 innings on Saturday in New York.
Price said he spoke with Maddon on Tuesday, and for now, the only precaution the Rays are taking in using the rookie out of the 'pen has been to give Price more advance notice so he can warm up properly.
The top pick in last year's First-Year Player Draft, Price may also still be in line to make a spot start in Tuesday's doubleheader in Baltimore.
"I won't hesitate to use David in the bullpen [Thursday] if I want to," Maddon said. "And as we go further along, he may be set up for that [start on Tuesday]."
Other options would include right-handers Mitch Talbot and Jeff Niemann, although Maddon said he would be more inclined to go with Price or Talbot since both have recently taken the hill. Talbot tossed three innings on Monday in relief of starter Scott Kazmir.
Maddon said the club won't have to set Tuesday's starter until Saturday, so if Price were to be used Thursday or Friday, he could still be a candidate for the role.