The South African-born playmaker is free to speak to other clubs following the Bairns' relegation to the SPL even though he has a year left on his current deal. Falkirk manager Steven Pressley is keen to retain the 28-year-old for their assault on the first division next season but privately realises that the lure of the top flight could prove too strong.
Hughes brought O'Brien, who started his career at St Mirren before moving onto Blackburn Rovers and Livingston, to Falkirk in summer 2008 following his three-year spell in England with Sheffield Wednesday.
O'Brien has made 67 appearances for the Bairns in two seasons but was not able to prevent Pressley's side from dropping to the first division last month after they failed to beat Kilmarnock in a dramatic final day decider.
This wouldn't be the first time Hughes has raided former club Falkirk as he, Kevin McBride and Patrick Cregg were among the first players he recruited after taking the helm last summer.
Meanwhile, James McArthur's agent has played down reports linking the Hamilton midfielder with a move to Leeds United. The 22-year-old has attracted interest from several clubs, including Rangers, West Brom and Wigan, but the player's future remains in the balance.
Agent Willie McKay said: "I've not had any contact myself and I don't think Hamilton have had either. I know (Leeds chairman) Ken (Bates) because I lived in Monaco and he was obviously there, but there's nothing really there.