The Giants’ ultra-durable and reliable ace, Logan Webb, landed on the injured list for the first time in five years, and while that might be cause for concern for some fans, it appears to be a somewhat precautionary move.San Francisco placed Webb on the 15-day injured list on Saturday with right knee bursitis after Giants manager Tony Vitello initially told reporters on Friday that he expected Webb to make his next start if the training staff was OK with the decision.That begs the question, is Webb’s injury more serious than it initially was believed to be, and what exactly is knee bursitis? NBC Sports Bay Area spoke to Marc Safran, M.D., the professor of orthopedic surgery at Stanford Medicine, about Webb’s injury.“Bursitis stands for inflammation, if you will,” Safran said. “It’s inflammation of the bursae. A bursae is kind of like a water balloon that has a little bit of fluid in it, kind of like oily fluid that lets the tendon or soft tissue slide past the bone without undue friction. So it just kind of helps it glide around, and sometimes it can get inflamed from any number of causes and the inflammation is the bursitis that causes...