But as burdensome as both of those tasks are, they're not even Fielder's main concern.
Heck, he had a tougher fight on his hands just trying to get back in the NFL two years ago.
Fiedler's No. 1 problem right now is he and his receivers have struggled to find their rhythm.
In last week's 13-7 loss at Minnesota, Fiedler and his receivers suffered numerous communication breakdowns. Both parties have admitted fault, but the fans have already began yelling that backup quarterback Damon Huard should be playing.
"I'm not worried about any of the public criticism," Fiedler said. "The only criticism that matters to me is the one that's in this locker room right now, and I haven't gotten any."
Fiedler didn't get criticized by Marino, either, but a few weeks ago Marino, who works as an NFL analyst for HBO's "Inside the NFL," said he thought Huard should been named the starter.
Fiedler shook that off to lead the Dolphins to a 23-0 season-opening win over Seattle. But against Minnesota, Fiedler was 12-for-31 passing for 175 yards, with one interception and one touchdown.
On one play, Fiedler threw a pass to Tony Martin, only Martin was blocking. The errant pass fell at the receiver's feet.
On a third-and-16 play, receiver Leslie Shepherd ran a 15-yard route when the play called for an eight- to 12-yard route. While Shepherd was going upfield Fiedler was standing in the pocket, pumping the ball, waiting for Shepherd to make his break.
That pass, too, fell incomplete.
"I think I need to be a little bit more accurate with some throws," said Fiedler, a Ivy Leaguer who attended Dartmouth. "I felt we saw everything OK. I think we picked up most of the blitzes. ... From my standpoint, I just have to be a little more accurate putting it on the receivers to give them a chance to run away from the defender."
Fiedler's job will be even tougher Sunday because Martin, the Dolphins' best deep threat, was put on the inactive list due to a foot injury.
That means Fiedler, who missed most of training camp due to a hip injury and won the starting job after playing one half of a preseason game, will be without his top three receivers Sunday. But Fiedler has been in at least one tougher situation.
Fiedler spent his first two NFL seasons (1994-95) as a reserve for the Philadelphia Eagles. Released during training camp in '96, he was picked up by Cincinnati, but was released a month later and spent the year out of football.
Desperate to earn a NFL job, Fiedler and his agent, Brian Levy, sent each NFL team a letter of recommendation from Fielder's high school coach and 23 minutes worth of college highlights.
The Minnesota Vikings, liked what they saw, and signed Fiedler because of an ankle injury to starter Brad Johnson. (It also turned out Vikings coach Dennis Green remembered recruiting Fielder when he coached at Stanford.)
Fiedler played in five games for Minnesota in 1998, and was 3-for-7 passing for 41 yards, and he left a good impression.
"He has very good accuracy," Vikings receiver Randy Moss said. "He throws a nice football. He's an NFL quarterback. I liked Jay. I had no complaints or negatives about him. He was quiet, and he knew the game of football."
After hearing rumors the Vikings might select quarterback Daunte Culpepper in the draft, Fiedler signed with Jacksonville, where he made his only NFL start before this year.
As far as replacing the legend of Marino, Fiedler realizes that will never happen. But he has a level-headed approach to filling Marino's shoes.
"Every week is a new week," he said, "and I'm just going to attack each week just like that, starting from scratch."
NOTES: Dolphins defensive tackle Daryl Gardener, suffering from a herniated disc, is out indefinitely after back surgery yesterday, ending his streak of consecutive games played at 66. He leads Miami in quarterback hurries with five, and also has nine tackles and a half-sack. No timetable has been set for his return. ... Defensive end Kenny Mixon will start at tackle alongside Tim Bowens, with Rich Owens taking Mixon's place at end.