[11] In 2002, he purchased the York Region Shooters franchise in the Canadian Professional Soccer League from Frank Bisceglia.

[12] The following season the Shooters merged with the Vaughan Sun Devils to unify the York Region territory with De Thomasis becoming the principal owner.

[13] After the acquisition Vaughan reached the CPSL Championship final in four consecutive seasons, and clinched their first piece of silverware the Eastern Conference title in 2005.

[16][17][18] In 2010, he received the Harry Gauss Memorial Award for his continual allegiance, commitment and support to the league.

[20] In 2018, he formed a partnership with former player Filipe Bento to launch Unionville Milliken SC in League1 Ontario.