Reading this question, I had a couple thoughts. Questions. The answers to the questions indicate how to handle the scene.

1. First, is it necessary to distinguish which boy is doing what? Does it matter or are you mainly trying to get across that two boys are being chased? If it doesn’t matter, then don’t worry about it. Just describe what’s happening and let the reader know that there are two boys. If the reader wants to know which boy is doing what, let them figure it out for themselves.
2. Second, though, if it is important to differentiate the boys, can you include dialogue? (Depends on whether they are in a situation where talking/whispering/shouting is appropriate.) If dialogue can be included, then use dialogue tags. (You can find out about dialogue tags in previous posts on my web page if you don’t know what I’m talking about.) Dialogue tags are wonderful. Fabulous.
3. Thirdly, if it is important to differentiate the boys and you cannot include dialogue, then choose something about each boy that can quickly and easily be described, like unusually long hair or a torn pant legs or something more creative that you’ll come up with because you know the story. As you describe the chase scene, describe what’s happening to that special thing as the boys are trying to get away. Long, blonde hair got caught and had to be torn free. A torn pant leg ripped more each time something happened until the pant leg had to be be torn off completely. Or something else entirely. The description of what happens to the item will also be a description of the boy so the reader will be able to keep them straight.