Pantilimon's exclusion comes amid speculation that he is set to replace out-of-form City goalkeeper Joe Hart at home to Norwich on Saturday.
Romania boss Victor Piturca on Friday released a list of 15 overseas-based players for the two matches, which did not include 16-cap Pantilimon.
Roma's Bogdan Lobont was the only goalkeeper named in the list which also included Premier League defenders Razvan Rat (West Ham) and Vlad Chiriches (Tottenham).
"Our national team coach, Victor Piturca, today finalised the official Romanian list of 15 players from overseas clubs, who have all received faxes to note the players must convene for the two games against Greece," a statement on the Romania football federation's website read.
Pantilimon could still receive a call-up closer to the matches - the first leg is in Greece on November 15 - with the full squad to be finalised on November 9.
The additions to that squad are likely to mostly come from domestic Romanian football, with Steaua Bucharest goalkeeper Ciprian Tatarusanu preferred to start in Romania's last qualifier against Estonia.
The 26-year-old was preferred to Hart in City's Capital One Cup 2-0 win over Newcastle in midweek, when he made a number of key saves to send the match into extra-time.
Following Hart's own form issues, highlighted by his role in Chelsea's last-gasp winner at Stamford bridge last weekend, it has been speculated that Pantilimon would be installed in his place.
City boss Manuel Pellegrini was coy in the subject on who would appear in goal for City against the canaries in his pre-match press conference on Friday, saying; "Tomorrow you will know the answer."
Then asked whether it was a difficult decision, he said: "It is a decision I have to take every week with 22 players."
Romania will book their place at a World Cup finals for the first time since 1998 should they win their two-legged play-off against Greece.