Dunstan's inside game was sensational against the Power, collecting 20 disposals and eight clearances as the Saints dominated stoppages with 50 clearances to 29.
The 19-year-old South Australian also booted a goal in his side's narrow nine-point loss.
He managed 22 disposals in St Kilda's heavy loss to Greater Western Sydney on March 1 and Richardson said he had proven himself worthy of an AFL debut, possibly against Melbourne in round one.
"Yeah he does [look ready]; he's done everything right, he's had another impressive performance," Richardson said.
"His ability to win the ball inside, big-bodied to be able to take the pressure of the opposition … we were plus-[21] in clearances and we rate [Port's] clearance work really strongly, so for him to be a big part in that was impressive today.
"His form through all the games has been strong."
Dunstan too said he now felt capable of performing at the elite level.
The Adelaide local, who captained the state's under-18 side and played three senior games for Woodville/West Torrens last year, told AFL.com.au he would love to make his debut against the Demons.
"I've been all right the last couple of weeks, I've sort of found my feet a little bit – look, I'd be more than happy to play if I'm selected," Dunstan said.
"My high intensity running needed to improve a fair bit; obviously doing a senior pre-season helped that, and I need to keep working on my disposal and bodywork around stoppages.
"I've only come a little way and the body work and running will get better with another pre-season under my belt next year, but for now it's about the little things and just working hard."
Twitter: @AFL_Harry
