Tendon? behind right knee - outer side about 3 inches up from joint - was tight all day. Fine Sunday after 15 miles + 5k race, but upon waking Monday was slightly sore. Still that way on Tue, but did 3 repeats and it was fine while running. Will take it easy.
Probably caused by racing hard on Saturday, followed by longish run Sunday, though it didn't bother me on the weekend. But it didn't persist, so calling it recovered.