Is it possible to set up blog categories without changing permalink structure

When our blog was initially set up, the permalink structure used was /blog/%postname%/ We’ve had it that way for about a year now and have good SEO results. We want to create a press release category for the blog which should result in a permalink like /blog/press/%postname%/ But doing this breaks all of our SEO links. I know that we can use a plugin to create 301s for the broken links… but I’m just wondering if there’s another way to do this? Thanks.