The Ducati rider escaped serious injury on the opening lap of last week's Catalan GP after a huge highside before his leg was run over by KTM's Brad Binder.
The championship leader suffered extensive bruising and is still undergoing physiotherapy, but rode on Friday, finishing 20th in FP1.
Bagnaia said the morning's running was "more tough," but an adjustment to his rear brake lever helped him improve for second practice to go straight to Q2.
Asked whether he felt better or worse than he had thought, he said: "I was hoping more that I was feeling better this morning because honestly, I can't move the foot because I feel pain from the haematoma.
"This morning was more tough because I wasn't understanding where to put the foot. This afternoon, we moved the rear brake lever because I was pushing on the rear brake lever and losing the rear in all the fast corners and it was quite scary.
"But this afternoon I understand where to put the foot, where I can't lean like usual, but we did a good step in front.
"The pain is quite intense but I feel a bit better compared to this morning, because we were competitive, and this is something which also helps a lot, but let's see.
"Honestly, I don't know what to expect from tomorrow, but right now being in the top 10 today was like a pole position.
"I was quite emotional after the practice, all the team was, but we can be very happy and satisfied with the result we did today."
Despite his strong showing on Friday, Bagnaia said he "didn't want to think" about how he would perform on Saturday, and said he needs to rest and have more physio.
He also said it was "very difficult to know" how much performance he was losing given his struggles with his foot.
"What I feel is that normally I put out my leg to help me have to more balance and to brake more, and I can do it, but it's not the same – I'm more unstable on the braking," he added.
"This is for sure something that is a bit limiting, but when I had to lean, I missed a bit of the lean angle.
"I really can't force on doing that with the leg and it's a bit of a limitation but we have the luck that this kind of track has a lot of grip and the tyre consumption is not so high, so I can turn the bike with the gas."
