Every soccer player needs a pair of soccer sandals or slides to put on before and after playing. Sliders from Nike, adidas and UnderArmour come in a one piece strap design or with an adjustable velcro strap. Slides with a memory foam foot bed are extremely comfortable to put on after playing a long hard match.
After playing a soccer game your feet need time to recuperate and walking around in cleats does not benefit your body or your cleats. Players need to take their cleats off after a game and put on sandals so their cleats don't get worn out especially if you are walking across a parking lot. Sandals or slides easy pop on or off when you are ready to change.
Having a pair of sandals in your bag can extend the life of you soccer cleats as well. Cleats are made for grass only for both for the benefit of your feet as well as the cleats themselves. If you walk across any concrete surface on cleats the studs will wear unevenly and that will affect the performance of your shoes when you need them most.