When talk of a professional rugby competition, or a "Rugby League", was being aired, Messenger was instantly interested by the development. He was approached by a consortium that included Test cricketer, Victor Trumper with friend J. J. Giltinan, who knew getting Messenger on board would be a major boost for the new code. He signed on with the new professional code in 1907. As the premier rugby footballer of the time, Messenger's signing is considered an integral moment in the foundation of rugby league. After he became a professional rugby league footballer, Messenger's rugby games were struck from the record books of the New South Wales Rugby Union and not restored for 100 years.