Although he’s out of the lineup for a third straight game with a stiff back, Alex Rios said he’s not concerned. The White Sox outfielder headed to the doctor for an MRI on Monday morning but said because he has experienced the same before and knows what to expect. Rios injured the back in the weight room on Saturday morning but thinks he won’t be affected long term. “I don’t think so,” Rios said. “It’s a thing that’s going to take a few days. It’s going to have to wait it out. It will be fine. I’ve had this before in my career. It’s just a normal (stiffness).”