Kazza, you won't like my solution, but I'll give it to you anyways.
I manage the Reserves myself.
I make a list of my upcoming matches, and use a three-letter initial for each of the players I intend to start, so it'll look something like this:
<pre class="ip-ubbcode-code-pre"> GK DL DR DC DC DMC ML MR AMC SC SC1-08 Pre A LIVERPOOL Ben Smi Ale Tay Joh Phi Ham C.R Kel Ric Gal1-12 Cup H Gravesend & N Tho Jon Mat Tay Fer Giv Chr Mil You Gal Bur1-15 Pre H Middlesbrough Ben Smi Ale Joh Fer Phi Ham C.R Kel Ric Bur1-22 Pre A MANCHESTER UTD Ben Smi Ale Tay Joh Phi Ham C.R Kel Ric Gal1-25 Pre H Fulham Ben Jon Mat Tay Fer Phi Ham Mil You Ric Bur</pre>
Now, if I have a Reserve match on the 11th, I can see that I've got an F.A. Cup match against Gravesend the following day, so I don't want to start Thomas, Jones, Matthews, or the other guys listed as starters .. so I don't. I want them fresh for tomorrow's rare senior runout.
When I get a Reserve match on the 18th, though, I know that Thomas has no games coming, while Jones and Matthews haven't played since the 12th and aren't scheduled to play until the 25th .. so they need a match.
Hey, I told you you weren't going to like it!