The undefeated Miami Dolphins are confident, yet cautious, knowing that sustaining their early success likely won't be easy over the next three games.

Seeking their best start in more than a decade, the Dolphins face the banged-up Atlanta Falcons on Sunday in their home opener.

Miami is looking to open 3-0 for the first time since 2002, and when it most recently started 2-0 in 2010, it finished 7-9. Prior to this year, the Dolphins were 5-18 in September over the past seven seasons. They've had only one winning season in that span, so it's understandable if the team is cautiously optimistic going forward.

"It's only two games," Miami cornerback and former Falcon Brent Grimes said. "But we played well and got two road wins to start the season, which is a big deal, and we showed a lot of promise of things we can do if we keep our heads on straight."

That humble and levelheaded attitude could be essential for the Dolphins, who face expected playoff contenders Atlanta (1-1), New Orleans and Baltimore in consecutive weeks.

"Any time you start 2-0 it's a confidence builder," linebacker Philip Wheeler said, "and we're going to feel like we can beat anybody."

Miami already proved that with last Sunday's 24-20 victory over an Indianapolis team which made the playoffs last season and hadn't lost a home game in nearly a year.

Ryan Tannehill was 23 of 34 for 319 yards and a touchdown to Mike Wallace, who matched a career high with nine receptions for 115. The high-priced receiver was in a better mood than the previous week when he pouted after catching one ball in a 23-10 win at Cleveland in his Dolphins debut.

Tannehill is expected to play despite being limited in practice by a sore shoulder.

A Miami run game limited to 20 yards against the Browns totaled 101 last week, including 69 and a touchdown on 14 carries from Lamar Miller.

"You have to stay true to the film," coach Joe Philbin said. "The film tells us from Sunday's game we did a lot of good things. But the film also says there are major areas of improvement that need to be addressed quickly. I think our guys are levelheaded and know film is the biggest barometer of success."

Philbin's team understands the amount of preparation it needs to face the Falcons, who are still extremely potent despite being hit hard by injuries through the first two weeks.

Most notably missing will be running back Steven Jackson, who scored his first touchdown with Atlanta and also injured his thigh during last Sunday's 31-24 win over St. Louis.

"He will not play this week. I know that," coach Mike Smith said. "It is short term. When I say short term, I don't know if it's two weeks or three weeks."

Atlanta also lost fullback Bradie Ewing (shoulder) and defensive end Kroy Biermann (Achilles) for the season, and linebacker Sean Weatherspoon (foot) for a minimum of eight weeks. Starting left tackle Sam Baker (knee, foot) also has been ruled out for this game, and a thigh injury could sideline cornerback Asante Samuel.

"We've not had anything close to this," Smith said about the rash of injuries. "There have been games where we've had guys who have not been able to play and it's been the next-man up mentality and I think that's really what our guys understand."

While Jacquizz Rodgers and Jason Snelling are expected to share the running back duties, slowing down Matt Ryan, Julio Jones and Tony Gonzalez presents the biggest challenge to the Dolphins defense.

Jones ranks among the NFL leaders with 18 receptions and 258 yards. He caught 11 for 182 against the Rams, including an 81-yard TD from Ryan.

"Julio and Matt seemed to be in sync, seeing the defense the same way," Smith said. "When you have your receiver and quarterback doing that, you have a chance to be successful."

Ryan, 33 of 43 for 374 yards with two touchdowns last week, is second in the league in completion percentage at 71.6.

Gonzalez has been targeted 14 times in two games while catching seven passes for 69 yards and a TD. He could be in for a big performance against the Dolphins, who have allowed a combined 13 receptions for 177 yards and two touchdowns to young tight ends Jordan Cameron of Cleveland and Coby Fleener of Indianapolis.

Atlanta won the last two meetings with Miami, most recently 19-7 at home in 2009. Ryan threw for 229 yards and two touchdowns, including one to Gonzalez, who finished with five receptions for 73 yards.