Santa Clara >> Upon further review, maybe Ricky Pearsall Jr. wasn’t actually physically able to play another game Monday.

The 49ers’ rookie wide receiver, fresh off playing 48 snaps in his NFL debut in a 28-18 loss to the Kansas City Chiefs, was working off excitement and adrenaline when he told the assembled media he was ready to play again the following day.

“Maybe I spoke too soon,” Pearsall said Wednesday as the 49ers began preparation for their Week 8 game against the Dallas Cowboys at Levi’s Stadium. “I was a little sore, had a little neck soreness, but that’s really all I was feeling. Probably because I haven’t received any contact or any kind of punishment.”

It could be that Pearsall is in for another 48 snaps or more Sunday night as the 49ers will attempt to go into their bye week with a 4-4 record. Brandon Aiyuk is out for the season with a torn ACL and MCL. Leading wide receiver Jauan Jennings is coming off a right hip injury that sidelined him for the Chiefs game. Jennings didn’t practice Wednesday.Deebo Samuel was ill — he was later hospitalized with pneumonia — and played just four snaps. Samuel was on site Wednesday and wasn’t practicing. During the media practice window, Samuel was running on the side. Tight end George Kittle (foot sprain) also didn’t practice.

Coach Kyle Shanahan is holding out hope that all three can face Dallas, but it’s far from a sure thing. If Pearsall’s debut was like being pushed into the pool to learn how to swim, his challenge against the Cowboys could be akin to being thrown off the high dive.

Pearsall, 24, will be a central figure in a nationally televised game based on his remarkable story of being shot in the chest on Aug. 31 during a robbery attempt and then coming back to play six weeks later. But Pearsall missed a lot of practice time, and even before the incident was limited in the offseason and in training camp because of a partial shoulder dislocation.

In the end, Pearsall caught three passes for 21 yards in five targets from quarterback Brock Purdy, numbers that would be less than impressive if not for his remarkable personal story.

Having worked out the soreness from Sunday, Pearsall was eager to get back at it Wednesday.

“I’m excited for practice and meetings,” Pearsall said. “That doesn’t change for games. I’m just playing football, what I’ve been playing since I was 6 years old. But I’m definitely looking forward to some opportunities.”

Primarily trained as an “X” receiver or split end, Pearsall opened the game that way but as the day went on he got in some snaps at flanker, in the slot and went in motion.

“I don’t think they planned on me having the role I ended up having, but after B.A. went down and Deebo was sick, I was working different positions,” Pearsall said.

Shanahan believes Pearsall will profit from the work he got against Kansas City and noted that he had no “busts” in terms of route mistakes while playing different positions.

“The more he plays, the better he’s going to get,” Shanahan said. “You can see that in practice. It’s only going to help him going forward. (He had) more reps in the game than anticipated with guys going down, and he’ll get more comfortable every week.”

One of the reasons Pearsall was selected in the first round was his ability to play at any receiving spot in the 49ers’ offense.

“Ricky is plug-and-play with all routes,” Shanahan said. “It’s not like he has a small route tree. He can run the whole tree.”

Pearsall’s overall impression on how he fared?

“I saw a lot of room for improvement, to be out of training camp and this period of time, there’s a lot of opportunity for me to get better,” Pearsall said. “I’ll just go back and grind, do what I normally do and work hard.”