Liverpool-born Whelan, 21, played three first-class matches for Middlesex, the last of which was in April at Oxford UCCE, and took a total of 11 wickets.

"I have been aware of his talents for a couple of years," director of cricket Steve Rhodes enthused.

Whelan added: "I'll be spending much of the winter in Sydney and cannot wait until March when I'll be raring to go."