Flynn entered the game with 8:22 left in the third quarter and the Packers trailing 20-7 after coach Mike McCarthy pulled Scott Tolzien, who had started the last two games.
"We were looking for a spark. That's directly what the communication was," McCarthy said. "We thought we had some opportunities early. We have a history with Matt.
"Did I think he was necessarily ready as far as the amount of reps and everything getting ready? That was not available to him since he's been here, but he went out and played football and did a lot of good things today."
McCarthy would not commit to Flynn as his starter for Thursday's game against the rival Detroit Lions.
"I don't have [an answer] for you," said McCarthy, who acknowledged he has "no idea" whether injured star Aaron Rodgers will return for the Thanksgiving matchup against Detroit.
Flynn passed for 218 yards to help the Packers storm back from a 16-point deficit, but the teams could only muster field goals in overtime Sunday. He became the fourth Packers quarterback since Rodgers broke his collarbone Nov. 4 against the Chicago Bears.
"We need to sit down as a staff, frankly, and talk about the things that went on today and how that affects our planning for Detroit," McCarthy said. "Just like we always do when we step away from the staff room, we'll do what's in the best interests of our football team and gives us the best chance to win."
Flynn, who spent his first four NFL seasons as Rodgers' backup before leaving in free agency following the 2011 season, re-signed with the Packers on Nov. 12 after Seneca Wallace sustained a season-ending groin injury.
A week after throwing for 339 yards in a loss to the New York Giants, Tolzien completed just 7 of 17 passes for 98 yards against the Vikings. He scrambled for the Packers' only touchdown, scoring on a six-yard run in the first quarter, but was pulled after going three-and-out on the Packers' first possession of the second half.
Information from The Associated Press was used in this report.