Matt Cassel hopes to showcase the improvements in his game when the Patriots take on the 49ers on Sunday.

The Providence Journal / Mary Murphy

FOXBORO -- This is a big week for Patriots quarterback Matt Cassel.

He did just enough to help the Patriots win their first two games of the season, but he came crashing back down to earth in Week 3 in the Patriots' 38-13 loss to Miami.

He was incapable of consistently moving the offense up and down the field, and if the Patriots' defense doesn't improve, just "managing" the game might not be good enough. He will look to get back on track Sunday against San Francisco.

Cassel said yesterday that his game has improved since taking over the quarterbacking duties for Tom Brady last month, and he hopes to showcase that this weekend.

"I have developed a lot in a number of different areas," Cassel said. "Most of it, I think, is feeling the game speed, continuing to see different looks and continuing to feel how different teams are going to attack you."

Cassel said he spent much of the Patriots' bye week watching film and working on his mechanics. By watching film, he is able to see where teams attack from and what area of the field is open during different defensive formations and blitzes.

He also got a chance to further improve his chemistry with his wide receivers.

"Anytime you can get out there and work on things that you feel like you're maybe a little bit deficient in, and also build on those things that you've done well, it's always good to have that week, and we were able to utilize that," Cassel said.

Wes Welker, who leads the team in receptions (19) and receiving yards (178) has been Cassel's go-to guy so far when he is in need of a big play.

"The more reps you can get out there with each other, the better it's going to be and the more you will be able to kind of read off each other," said Welker, who has caught a lot of wide-receiver screens.

Cassel also got Jabar Gaffney (6 catches, 51 yards, 1 TD) into the mix against Miami.

"For me, I drop back and if somebody is open, I am going to throw him the ball," Cassel said. "That is really what it is. You can work on routes all day in practice but in the game what it comes down to is if somebody is open or not."

Cassel has yet to find the on-field chemistry with All-Pro receiver Randy Moss, mainly because teams always put one defender on him and then often times roll a safety over toward his side for added help.

Knowing that Moss is double-covered in those situations, Cassel tends to look for a receiver that is in single coverage.

"You would always like to get Randy involved," Cassel said. "I don't really have much to do with that other than the fact that I go through my reads and I let the coaches game plan and do the things to get Randy the ball."

Moss has exceptional play-making ability, but even so, Cassel never feels tempted to throw the ball deep to Moss when he is double-teamed, like Brady used to.

"You have to go through your reads and you have to make smart decisions, because if you start forcing it in to double coverage you will get into bad habits and that is when bad plays happen," Cassel said. "As much as you would like to get the ball to him as much as possible, you still have to be smart with the football, especially as a guy in there trying to make the right decisions with the ball."

Cassel believes that it won't be long before he and Moss have a big game together.

"It will happen," Cassel said. "We are growing together and our chemistry is growing together. We will be fine."

Moss said that Cassel's playmaking ability will grow with his confidence.

"Well, I think that first of all he has to believe in himself," Moss said. "I think it will trickle on down to the whole offense. We have seen Matt progress in these last couple of weeks quicker than we expected him to. We just have to put guys around him. Luckily he is the quarterback, so he gets the good and the bad.

"With the 10 guys that we put around him, we have to make it happen. Not really everything is on him or his shoulders. He has to be smart and distribute the ball, but at the same time there are still 11 guys out there that have to get the job done. We like what we are doing as a whole offensive unit, and hopefully we can keep it going."

Cassel certainly believes in his ability.

"I have never really had a lack of confidence," Cassel said. "It is just getting out there and performing with those guys. I am a strong believer in, 'I wouldn't be in this position if the coaches and everybody else didn't have confidence in me as well.' That gives me a big boost."

Cassel will have all of his playmakers at his disposal on Sunday as starting running back Laurence Maroney, who missed the Patriots' last game with a shoulder injury, will be on the field against San Francisco.

"It is great with Laurence back," Cassel said. "The running backs have done a great job all year. They continue to do that and they give us a big lift. It is great to have Laurence back this week, and it will continue to help us on offense."

Slowly but surely, Cassel is becoming comfortable running the Patriots' offense.

"The more I get out there and the more experience I get, the more comfortable I will become," Cassel said.