The Scot, now 35, is on a list of eight possible riders in the GB Men's road race squad for the Games. Five of those names will go on to compete, so it is possible that Millar may not race.
Millar, who was banned in 2004 after admitting to doping, is the most contentious name on a strong-looking GB squad.
The British Olympic Association's policy of issuing life-time Olympic bans for drugs cheats was overturned in April by the Court of Arbitration for Sport, allowing Millar to be selected.
18 athletes were formally named by the Great Britain Cycling Team for the Olympics, with several Olympic champions amongst the line-up.
Sir Chris Hoy, Bradley Wiggins, Nicole Cooke and Victoria Pendleton were all included, along with road race world champion Mark Cavendish.
Hoy is up against Jason Kenny for the sole individual sprint berth, but decisions over which cyclists will compete in which event have not yet been declared and are expected to follow 'in due course'.
Full Team GB Olympic squad
Cross Country Mountain Biking
Men’s Road (five to ride)
Women’s Road (four to ride)