At an early age he played with the Lindfield Rugby Club while being educated at Saint Ignatius' College in Riverview, New South Wales.

[3] However, in 2010 he joined Eastern Suburbs, where again Coolican found himself finishing second in the JR Henderson Shield Grand Final, losing 12–3 to Randwick.

In 2013, Coolican left Australia for the United States after he received an invitation to return to America to play with the acclaimed New York Athletic Club (NYAC).

In the return fixture, Coolican again replaced Thiel at the 74th minute, to play a small part in the 32–13 win to qualify for the 2015 Rugby World Cup.

[8] He played a prominent part in the 2014 Pacific Nations cup, culminating in making a match winning charge down vs Canada in Sacramento.