Hartley kicked in 57 games for the Saints from 2008-13. He made 82-of-101 field goals, and all but one of his 177 PATs. The Saints released him last December after he missed twice in a loss to St. Louis. He made 22-of-30 kicks in 2013, a percentage among the league's lowest and 13 points below the league average at the time of his release.
Cundiff received an injury settlement after hurting his knee in a Thursday workout and missing Friday's practice. He had missed five kicks the past five games -- one on a 60-yarder in Atlanta, when he made the game-winner on the last play of the game. The last two weeks he missed kicks of 37 and 40 yards that could have made increased the Browns' leads to 10 points.
On Thursday, the team seemed to be standing by Cundiff. Coach Mike Pettine even said he expected Cundiff to kick on Sunday against Cincinnati and special teams coach Chris Tabor raved about Cundiff's morning workout at FirstEnergy Stadium.
"I thought he kicked the ball as well as I've ever seen him," Tabor said. "It's just one of those deals that ... there are some other things that sometimes go into it, but if he strikes the ball the rest of the season like he did today, we'll be in great shape."
Cundiff appeared on the team's injury report on Friday with a knee injury, which the team said happened during the workout. Cundiff said any questions about the injury should go to the head coach.
One source told ESPN that Cundiff sprained his knee in Thursday's practice and needs to miss 5-7 days, so he could have not kicked Sunday.
Tabor added on Thursday that Cundiff was 22-for-29, with a blocked kick and a miss from 60 yards.
"In my mind, that's 22-for-27, and that's five missed kicks, which would put him roughly around 81 percent," Tabor said.
Coincidentally, 81 percent is the exact career mark for Hartley in his five seasons with the Saints.
Cundiff made reference after the loss to the Colts about kicking outdoors in Cleveland, a place former kicker Phil Dawson used to call the toughest place to kick in the league. Sunday's weather calls for a 40 percent chance of rain , with 10-15 miles per hour winds and temperatures in the mid-40s.
ESPN.com's Jeremy Fowler contributed to this report.