Hey Kevin, sorry about tweaking your shoulder.
On an earlier post, I saw someone mention how beneficial tempo work was for them when they were playing rugby. I've always been a fairly decent runner, and I attributed that to quite a bit of tempo running. My tempo runs typically lasted 5-12 minutes, and I think that was the magic area for maintenance and improvement of speed AND endurance. In fact, when I was training for half and full Ironman tris a couple years back, I would have one LSD run per week, and my other stand-alone running workouts were tempo runs. There were also some brick runs off the bike, but that was more a survival shuffle more then anything....
Nice first day back though.