If New Orleans Saints opponents thought they had caught a break when veteran receiver Joe Horn or rookie sensation Marques Colston went down recently, they were mistaken.

Devery Henderson and Terrance Copper have made big plays filling in, helping New Orleans maintain the most prolific passing attack in the NFL.

“It’s fun to know that with this offense that we have the ability to do so many things,” said Saints quarterback Drew Brees, whose 3,463 yards passing leads the league. “I’m happy for the guys around me — the guys like Devery Henderson, who has stepped up and played so well.”

Colston, the league’s leading receiver through his team’s first nine games, sprained his left ankle only a few plays into a game against Cincinnati two Sundays ago and has not played since. Horn missed the two games prior to that.

All the while, Brees kept firing, putting up more than 300 passing yards in each of the last four games while connecting more often with Henderson and Copper.

Henderson, known coming out of LSU for his dramatic 74-yard, “Bluegrass Miracle” touchdown catch in a last-second victory at Kentucky in 2002, has had the best run of his young pro career the last month. In a victory over Tampa Bay four games ago, he had 111 yards receiving, including touchdown catches of 52 and 45 yards.

In a loss to Cincinnati, he caught nine passes for 169 yards. Then, in last week’s victory over Atlanta, he caught four passes for 158 yards, including a 76-yard touchdown in which he cleanly sprinted past the coverage for the catch and went untouched into the end zone.

Henderson, now tied with Joe Horn for second in receiving touchdowns with four this season, credited the approach of new coach Sean Payton and his staff for the consistency of the passing game even as key receivers have missed games.

“We feel that at any time somebody might have to step up. That was understood from Day One. The way we prepare at practice and everything, we’re ready for it,” Henderson said. “When one guy goes down, it’s like we don’t miss a step. The other team has to fear the next guy just like a starter is in there.”

Take Copper, for example. He was picked up off waivers after training camp and began the year as a special teams player. Suddenly, Horn’s injury thrust him into the third receiver’s spot.

In the Saints’ last three games, he has 13 catches for 217 yards and three touchdowns, including a TD on Brees’ 48-yard heave at the end of the first half in Atlanta last Sunday, a catch replayed numerous times on national highlight shows.

“That’s encouraging because you don’t know how it’s going to go,” Payton said. “When we lost Horn before the Tampa game, we were able to still effectively execute. You’re never going to go through the season with the same set of receivers.

“There’s always going to be a nick or a change and fortunately we’ve been able to fill in and guys have been able to step up and play some whether it’s Devery Henderson or Terrance Copper. We just keep preaching the little things and the technique and the fundamentals.”

Copper was having a few problems with fundamentals when he was first thrown into the receiving mix, fumbling while trying to get more yards after first-down catches two weeks in a row. The first of those fumbles ruined the Saints’ bid for a late-tying score in a loss at Pittsburgh. But Payton, who as a Dallas assistant coach worked with Copper during their past two seasons together with the Cowboys, stuck with the third-year pro. And Brees kept throwing to him.

“Coach knows that Copper has given as much effort as any guy on this team,” Brees said. “In this offense, everybody’s going to get an opportunity and (is expected to) take advantage of it, and Copper’s been one of those guys.”

Both Henderson and Copper have made dramatic strides this season.

Henderson played in only one game with no receptions his rookie year. He had 22 catches for 343 yards and three touchdowns all of last season, numbers he’s already easily surpassed this year with 548 yards through 11 games.

“I do a lot of things now that I didn’t do my first two years,” Henderson said. “I’m catching balls after practice, different drills that I didn’t do before. They really help.”

In Copper’s first two NFL seasons combined, he caught eight passes for 89 yards and one touchdown. He’s done far more than that in the past three games, thanks in part to Saints coaches sticking with him after his two turnovers.

“Coaches kept confidence in me, Drew kept confidence in me. My teammates kept confidence in me,” Copper said. “You’re going to face adversity sometimes and you’ve got to come back from it and basically that’s what I was trying to do. I always expected to come here and play and make an impact on the team. I wanted to contribute.”