A unique piece of Sheffield Shield history was seen on Tuesday after Jordan Silk copped a nasty knock from a Peter Siddle bouncer.
Silk suffered delayed-onset concussion after ducking into the bouncer in the first hour of play on Monday, and had to be replaced by concussion substitute Jake Doran.
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Silk had continued to field for Tasmania on Tuesday morning and took an excellent diving catch at cover to dismiss Daniel Christian (35) off the bowling of Tom Rogers.
However he couldn't bat when Tasmania went back in, with Doran allowed to bat in his place.
It is the first time a concussion substitute has been used since the rule was introduced to the Shield this season.
NSW's Daniel Hughes was the first player to come off under the rule when it was brought into the domestic one-day competition last year.
The importance of concussion management in cricket was tragically highlighted by the death of Phillip Hughes in 2014.
Hughes was struck on the neck by a bouncer during a Shield match and died in hospital two days later.
A coronial inquest later handed down a number of recommendations to be implemented across Australian cricket, including for prevention and management of head knocks.
Doran and veteran Alex Doolan dug in their heels to help Tasmania build a handy second-innings lead over Victoria.
Doolan was unbeaten on 107 with skipper George Bailey 30 not out as Tasmania went to stumps on day two at 1-180, leading Victoria by 208 runs at the MCG.
Doran and Doolan faced 263 balls together as Tasmania looked to slow the frantic pace of a game in which 20 wickets had already fallen before lunch on day two.
Their partnership came to an end when Peter Siddle had Doran (35) caught behind after tea.