Ten players were tested, having missed out on the opportunity to test at the national combine in Melbourne.
Players who had five or more clubs nominate them for testing were invited to the national combine. Those with four nominations or fewer were given their opportunity at the state screenings.
Claremont's Francis Watson spent two days on a bus from Broome after his step-sister paid for his ticket, just to get back to Perth for the combine, having gone home for a holiday.
East Fremantle's Ryan Lester-Smith, who is a potential father-son recruit to Fremantle, did not test due a knee issue and Claremont's mature-age forward Ian Richardson was overseas, having already done his testing separately.
The AFL's academies development manager, Mick Ablett, was in Perth for the WA combine and believes players will earn their AFL opportunity on the back of the state testing.
"History suggests that there's going to be guys come out of this," Ablett said.
"I remember Kane Mitchell coming and doing it twice in the last couple of years and getting his opportunity.
"I think from memory Matt Priddis did three state screens before he got drafted."
Ablett thought that Shanahan, who played colts and reserves with East Perth this season, and South Fremantle's Tim Kelly put in eye-catching displays.
"Thomas Shanahan, I thought he was super," Ablett said.
"I thought he showed good power (in the agility test). Obviously he's run a sensational beep as well.
"I thought Tim Kelly was really good.
"I thought he ran a really solid beep. I thought he tested really well in general."
Shanahan clocked 8.00 seconds in the agility test and 2.93 seconds in the 20m sprint. He also ran a 13.8 beep test to finish third behind South Fremantle's Ben Sokol (14.1) and East Fremantle's Jacob Green (13.13).
Shanahan was runner-up in the Jack Clarke Medal, the best and fairest for the WAFL colts competition, behind Green.
Ablett says the lower beep test results compared to the national combine should not be underestimated.
"It's a tough day for these boys when you look at the testing that they have to complete in a day, as opposed to what the guys do at the national combine, so when you see guys running in the 13s in the beep test, it's really impressive," Ablett said.
"I think sometimes (with) the expectation on the boys and where we see guys running 15s and 16s, we can sometimes overlook what other guys are doing through the other levels."
Shanahan credited his results to the extra training he had done after the end of his season in September.
"I did some sprint training with (WA track coach) Lyn Foreman, because I got told I needed to run a sub-three second 20m," Shanahan said.
"She did a great job and obviously it's worked."
The inside midfielder spend most of the year playing WAFL colts, averaging 25 disposals, and played the last four WAFL reserves matches including a semi-final.
"I've never been on the radar that much," Shanahan said.
"I'm pretty sure I got the late call-up compared to some guys.
"It's something that I sat down at the start of the year and wanted to achieve and I did. So I'm pleased."