McSheffrey began his professional career with Coventry City, and has previously played for Stockport County, Luton Town, Birmingham City, Nottingham Forest and Leeds United before returning to Coventry in 2010.
Released in September 2013, he signed for Chesterfield later that month.
In January 2014, he signed for Scunthorpe United on a free transfer until the end of the 2013/14 season.
McSheffrey has played internationally for England three times at both under-18 and under-20 level
The 35-year-old joins the Spitfires from Doncaster Rovers.
He began his career as a striker but eventually became a left-winger and has made more than 450 appearances in the Football League and Premier League, including 247 for Coventry, where he became the youngest player ever to play in the Premier League.
McSheffrey goes straight into the squad for Saturday’s trip to Guiseley AFC.