The 31-year-old joined the Eels, for whom he debut with in 1998, this season after a four year stint playing in France and six years with Brisbane prior.
A hooker-halfback, Eels CEO Paul Osborne could not confirm the extension on Monday – although acknowledged it was imminent.
“I think they are just nutting out the terms,” Osborne told Sportsnewsfirst.com.au.
“It is close.”
However Sportsnewsfirst.com.au has been assured by insiders that the deal has been agreed on.
McGuire is a former Queensland origin representative having twice played for them in 2005.
The crafty back has been a handy signing for the out of luck Eels shifting from hooker to halfback throughout the majority of the season.