Morstead, who averaged 50.8 gross yards per punt in the Saints' first eight games, gingerly left the field after a Broncos player rolled into his legs.
No penalty was called because referee Bill Vinovich ruled that a Saints player blocked the defender into Morstead.
As a result, the contact was legal. That didn't help Morstead, who wound up punting four times for a 40.8 gross average and 36.5 net average in finishing the game.
After the game, he said he didn't know the extent of the injury, which isn't good since the Saints have a short turnaround this week with a Thursday night game against the Carolina Panthers.
"I got a lot of good juice running through me right now, so we'll wait and see," said Morstead, who was second in the league in both gross average and net (44.6 yards) going into Sunday's contest.
--Saints quarterback Drew Brees threw three touchdown passes in Sunday's loss to the Broncos, pushing the total for his 16-year NFL career to 452.
That's good for third place on the all-time list and the three scoring strikes leave the 37-year-old Brees just 88 shy from setting the NFL record for career touchdowns passing.
Brees' first touchdown of the afternoon, a 3-yarder to wide receiver Willie Snead, marked the 59th consecutive home game that he has had at least one scoring pass -- an NFL record.