Biggar was given a three-week ban at Wednesday's disciplinary hearing, but if he applies for and completes a World Rugby Coaching Intervention, that would reduce by a week and he will be free to play on Monday, May 2.
That means he would be available for Saints' final two fixtures of the Gallagher Premiership regular season, at Saracens and at home to Newcastle Falcons.
However, he will definitely miss Saturday's trip to Bath and the following Friday's clash with Harlequins at cinch Stadium at Franklin's Gardens.
And EPCR statement read: "The Northampton Saints out half, Dan Biggar, has been suspended for three weeks following an independent Disciplinary Hearing arising from his club’s EPCR Challenge Cup, Round of 16 match against Gloucester Rugby at Kingsholm.
"Biggar was sent off by the referee, Sam Grove-White (Scotland), in the 51st minute of the match for tackling the Gloucester Rugby centre, Chris Harris, in a dangerous manner in contravention of Law 9.13.
"Law 9.13 A player must not tackle an opponent dangerously
"Under World Rugby’s Sanctions for Foul Play, Law 9.13 relating to dangerous tackling carries the following sanction entry points - Low End: 2 weeks; Mid-range: 6 weeks; Top end: 10 to 52 weeks.
"The independent Disciplinary Committee comprising Philippe Cavalieros (France), chair, Marcello d’Orey (Portugal) and Mitchell Read (England), heard submissions from Biggar, who accepted the red card decision, from the Northampton Saints Team Manager, Maurice Hartery, and from the EPCR Disciplinary Officer, Liam McTiernan.
"The committee upheld the red card decision, finding that in executing a dangerous tackle which warranted a red card, Biggar had made contact with Harris’s head. It was then determined that the offending was at the mid-range of World Rugby’s sanctions and six weeks was selected as the appropriate entry point.
"Given his guilty plea and clear disciplinary record, and as there were no aggravating factors, it was decided to grant the full 50 per cent mitigation and the committee therefore reduced the sanction by three weeks before imposing a three-week suspension.
"Because of Northampton Saints’ forthcoming fixture schedule, Biggar is free to play on Monday, 23 May, however, if he applies for and completes a World Rugby Coaching Intervention, he will be free to play on Monday, 2 May. Both he and EPCR have the right to appeal the decision."