Having already missed out on both the 2003 and 2007 World Cups in Australia and France, Henson will now not be considered for the initial 30-man squad this time around.
The 29-year-old will remain on standby, however, in case he is needed in the later on in the tournament if Wales suffer any further injury setbacks.
"He has been given a return to play time of six to eight weeks," said Wales' medical performance manager Prav Mathema.
"Whilst ruling him out of selection for the initial RWC squad, it could see him available to the coaches whilst we are still in the pool stages of the tournament.
"With that fact in mind, Gavin will remain under the care of the Wales national squad medical staff in order to ensure that he returns to fitness at the earliest opportunity in case the coaches need to call him out to New Zealand for any reason."
A six-week return could see Henson available for the third pool clash with Namibia, while an eight-week absence would mean a potential quarter final would be his first chance of action if called up to the squad during the tournament.
Henson, who is currently without a club after leaving Toulon at the end of last season, was making just his second international appearance in two-and-a-half years following a lengthy sabbatical. Ironically, that extended time out from the game was as a result of Henson's growing frustration with his injury misfortunes since making his first and so far only Lions adventure six years ago.
The news is a big blow to Wales coach Warren Gatland who had appeared keen to include the double Grand Slam winner when he names his squad a week today.
Henson had showed some promising touches in Saturday's win over England in Cardiff as he linked up with Jamie Roberts, the Lions' HSBC Player of the Tour from 2009, for only the second time. But the former Ospreys and Saracens star lasted only 32 minutes of the 19-9 victory, just a week after Scarlets full back Morgan Stoddart had seen his World Cup dreams shattered by a broken leg in the reverse fixture at Twickenham.