Lando Norris chose to limit his running in Styrian Grand Prix second practice to minimise aggravating some back pain the McLaren Formula 1 driver sustained earlier in the day.
The Briton, who scored his first F1 podium in last week's Austrian Grand Prix, reported feeling some upper back pain during the opening practice session at the Red Bull Ring.
Although he felt better after treatment between sessions, it was decided to restrict his running in second practice to avoid overstressing his body in the afternoon.
Norris completed 31 laps to end up eighth overall, three places behind team-mate Carlos Sainz Jr., who put in 45 laps.
Speaking to Sky afterwards, Norris admitted that he was "a bit on the back foot" and had limited his running "to make sure I'm in shape for tomorrow and Sunday".
"I feel fine now and walking around, but when I am driving it is something that causes me a lot of pain particularly in the high speed corners and when I'm braking," he said.
"I have spoken to my specialists and he tried to figure it out, but it is not as obvious as just pointing it out.
"I've been on pain killers and whatever, but it's been setting me back a lot today, so pretty frustrating.
"I have not felt confident in the car in terms of pushing it, so hopefully I can get it fixed and be ready for the next one."
As well as the back pain, Norris' morning session was also overshadowed by a three-place grid penalty he picked up for overtaking under yellow flags.
The youngster owned up to his error, after passing a slow Pierre Gasly while the caution flags were out for the stationary Williams of Nicholas Latifi.
"It's my mistake to be honest," he said.
"I was on a push lap, both of these guys were on an out-lap or a cool lap.
"I slowed up for the yellow flag, which you're meant to do, but I just continued to roll past the two other guys.
"It's my mistake. [It was a] bit stupid of me."