After uploading a video online that I made in Premiere Pro CS5, I noticed that the quality of the video has drastically reduced. I understand that uploading a video online will often lower the quality, but it's very bad in my situation.

Here's my video:
Untitled on Vimeo

Below are some screenshots of the sequence and export settings that I used
sequence:
http://i53.tinypic.com/35kk75d.png

export settings:
http://i53.tinypic.com/2ymggnt.png
http://i55.tinypic.com/6xytf8.png
http://i56.tinypic.com/25qg7jb.png

All clips were shot at 720p at 60p using my T2i.

It would be greatly appreciated if someone could help me, thank you in advance

I think the saturation in the master file has overcooked the 4:2:0 compression at Vimeo.

If you back the saturation off in AE by about 5% you may get a cleaner result.

The problem is that the shape of the players' shirts is defined by pure chrominance, which (at 4:2:0) is a quarter of the resolution of the luminance, hence the quality is okay on the background details, but the players look harsh.

Moved from Rebel T2i to Adobe Creative Suite.

Just use the Vimeo preset (H.264) it works wonderfully.