Strained a calf muscle? If so how long will it take to be able to walk on it again? I called off last night but I work tomorrow and I can't call off again without a Dr's excuse. I'd prefer not to go to the ER for a strained muscle. It started yesterday around 4 am and I've been off it (other than walking from my bedroom to the kitchen or bathroom) since yesterday morning when I got home from my night shift.