GREEN BAY, Wis. -- Perhaps Green Bay Packers fans have little faith in this year's team.

How else to explain why they are thousands of sold tickets short of a sellout for Sunday's NFC playoff game at Lambeau Field against the San Francisco 49ers? As of Thursday morning, according to a team spokesman, the team has 5,500 unsold tickets. On Wednesday, the number stood at 7,500.

The Packers have a streak of 319 consecutive sellouts (301 regular-season games and 18 playoff games) and nearly 100,000 people on their season-ticket waiting list.

The Packers must sell out by 3:40 p.m. ET on Thursday to avoid a local television blackout. NFL rules say teams must sell out games at least 72 hours prior to kickoff to ensure they will be shown on local TV.

Green Bay isn't the only team having trouble selling out for this weekend's games, with the Indianapolis Colts and Cincinnati Bengals also faced with thousands of unsold tickets.

The Colts, who have sold out 137 of their last 138 games, have 5,500 tickets remaining that they need to sell to avoid having their Saturday game against the Kansas City Chiefs blacked out in the Indianapolis area.

The league extended the Colts' deadline to avoid a blackout to Thursday at 4:30 p.m. because Wednesday is a holiday.

In Cincinnati, Jeff Berding, the Bengals' director of sales and public affairs, said late Monday that after a good day of sales, more than 10,000 tickets remained for Sunday's game at Paul Brown Stadium against the San Diego Chargers. That number dippedto 8,000 tickets as of Wednesday afternoon.

In an effort to sell more tickets, the Bengals kept their ticket office open on New Year's Eve and will do the same New Year's Day. According to Berding, the office will be open from 9 a.m. to 7 p.m. on Wednesday.

Bengals team spokesman Jack Brennan says the team is confident they can get an extension from Thursday to Friday to try to avoid a blackout.

The Bengals' ticket push has even become a civic issue in the city. On Monday, Cincinnati Mayor John Cranley held an impromptu news conference at the start of coach Marvin Lewis' weekly remarks to encourage fans to come out for the game.

The Packers, at 8-7-1, have the worst record among the 12 playoff teams.

The organization sent out playoff ticket invoices to season-ticket holders during the seven-game stretch in which quarterback Aaron Rodgers was sidelined because of a broken collarbone. When Rodgers returned for the regular-season finale Sunday and helped the Packers beat the Chicago Bears to win the NFC North, the team still had 40,000 tickets available for the opening round of the playoffs.

The team gave season-ticket holders another chance to buy seats on Monday morning before opening the sale to the public later in the day. A team spokesman said Tuesday the four-ticket limit per transaction that was in place Monday has been lifted.

The Packers added 7,000 seats this season behind the south end zone, bringing capacity at Lambeau Field to 80,750. The waiting list for season tickets was more than 100,000 people before the seats were added.

ESPN.com previously reported that owners can buy postseason tickets for 34 cents on the dollar to avoid blackout. While that is the case for regular season games, owners must pay full price for playoff tickets.

Ticket sales weren't a problem for the Seattle Seahawks on Tuesday, with the team saying it sold out in less than 30 minutes. The NFC's top seed opens in the playoffs on Jan. 11.

ESPN.com sports business reporter Darren Rovell, Colts reporter Mike Wells and Bengals reporter Coley Harvey contributed to this report.