The official source for Champions League matches is here:
You can change the Season number in the url to get previous years, or click on "History" in the upper right and select the appropriate season.
It is a little difficult to navigate, but you can get individual player distances for each match run. Here are the steps to find it (at least for the current season - I tried the same steps on other seasons and it seems they're different, which is annoying, but hopefully this might help you when searching for those other ones):
1) From the above page, click on the phase (Qualifying, Tournament) that you want, then click on "Matches"
2) Click on an individual match that you're interested in
3) Click on "MatchCentre"
4) Go partway down the right side, click on "Players", then click on the name of a player (on the right side) that you're interested in. The players stats will come up, which includes the distance covered (at the bottom).
Now, this will probably not help you that much, since it involves going to each individual player and entering them individually, which is unlikely to be practical, but hopefully it will help you find a better source.
Another possible source is here:
However, that shows summary statistics. It does have "distance covered" located up front, but it's summed over all games.