|"Is this all real? Or has this been happening inside my head?"
The topic of this article is of a real-life subject that has been mentioned "in-universe" in a canon source. The Harry Potter Wiki is written from the perspective that all information presented in canon is true (e.g., Hogwarts really exists), and, as such, details contained in this article may differ from real world facts.
James Leigh Hamilton (b. 17 November, 1982) was a professional rugby union player who played as a lock for the Scottish rugby team since 2006. It is possible he was related to the wizarding Hagrid family, given his strong physical resemblance to Rubeus Hagrid.
In 2014, Jim Hamilton, along with Kelly Brown and Stuart Hogg, came under suspect, among wizarding circles, of actually being a talented Squib. While there is no wizarding rule which prevents a Squib from actually playing on a Muggle team, the act of smuggling a Squib into the team, which is the rumoured mission of the WSSRU, is in violation of the International Statute of Wizarding Secrecy which prohibits wizards from participating in Muggle sports.