Lalor appeared to hit his head and neck when he was pushed into Eagles trialist Sandy Brock in a marking contest.
The 18-year-old was assessed by medical staff as he lay on the ground for about one minute before walking off the field.
Sam Lalor came from the ground following this contest.— AFL (@AFL) February 17, 2025🎥: Kayo Sports/Fox Sports pic.twitter.com/eAYDV3XOvh
Richmond head of development Sam Lonergan confirmed Lalor was being tested for concussion immediately after the match.
"He's got a bit of a sore jaw at the moment, so he's currently in concussion (testing) protocols," Lonergan told reporters.
"We'll just wait and see what that looks like and then hopefully find out pretty quickly over the next 24 hours.
"He was great today. He played a little bit in the midfield and spent some time forward, which was fantastic, and contributed in both areas of the ground."
Earlier, Lalor kicked the Tigers' first goal with a set shot in an even first period of three played at Mineral Resources Park in Perth on Monday.
But it was all West Coast after that as Tyler Brockman booted three majors in a comfortable 10.2 (62) to 4.2 (26) victory for the home side.
Tyrell Dewar almost pulled in a spectacular mark on an opponent's shoulders and provided a highlight with a superb goal on the run from 50 metres.
Tyrell Dewar turns on the jets and finishes from outside 50 🚀— AFL (@AFL) February 17, 2025🎥: Kayo Sports/Fox Sports pic.twitter.com/bMjOsHK5Vu
Former Carlton forward Matt Owies kicked his first goal for West Coast, while former Tigers Jack Graham and Liam Baker also lined up in Eagles colours for the first time.
West Coast captain Oscar Allen finished with two goals, as did Lalor for Richmond.Â
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