Improvements can be made if you have time. For instance, you could make individual pages via SimplePortal and import the content from Google Spreadsheet via an iframe in said page. The owner(s) must click on publish, then paste the link into something along the lines of the code available in the roster example page I just made.
http://www.profsl.com/smf/index.php?page=BackyardNHLRosterExample
So basically...
1) Make spreadsheet
2) Click on file, publish (that one I made has a clone of your existing one, as I cannot publish it without access, so don't think that updating your current spreadsheet will change that page - it won't)
3) Get the link
4) Make a new SimplePortal page
5) Grab the code from my example page
6) Replace the link with yours
7) Adjust SimplePortal page permissions or whatever other config you may need
8) Change existing blocks to link to the new page rather than the spreadsheet, could also recommend using <a href="whatever page link" target="_blank">Roster[/url] to make them open in a new tab rather than having to go back and forth.

Advantages are that it embeds the spreadsheet directly into the forum, and it could actually be expanded upon with the design and stuff, I reckon. Quite nifty and doesn't force users to go to the actual spreadsheet, away from your site.
Disadvantages? Time consuming, can't make iframes to be responsive (google dictates styles) so you will have to scroll the tables.