The duo have joined the Spireites on loan until the end of the season. Richardson told his club's website: "I am pleased we have eventually found two experienced left-sided players who will bring new options into the squad." Boertien, 28, has started over 100 games for Derby but has not figured since December, while Rizzo, 27, has been at Crystal Palace and Liverpool.
In his time with United Boertien made just 21 appearances, scoring one goal in the process, after a rapid rise through the youth ranks at Brunton Park. Paul's performances soon seeing him move on to Derby County for £250,000 in March 1999, the 28-year old has endured an injury-ravaged time with the Rams though and a move down a division will no doubt be beneficial for both clubs.