Ariel Helwani of Versus.com reports that Guida vs. Lashley will take place on the undercard of a night of fights that also includes Roy Nelson vs. Jeff Monson in MMA and the return of Roy Jones to the boxing ring, to face Omar Sheika.
Although Guida has been a professional fighter for several years and has 36 fights under his belt, he's known in MMA circles for two things: He's the less talented brother of UFC lightweight Clay Guida, and he missed an opportunity to appear on The Ultimate Fighter because he couldn't make weight.
Still, Guida will probably be a tougher opponent for Lashley than Shamrock would have been. Shamrock is so old and past his prime that no one seriously believed he had a chance of beating Lashley. Guida, though certainly an underdog and not a particularly good fighter (career record: 17-19), is at least a live body. Lashley should have his way with the much smaller, weaker Guida, but if I were Lashley, I'd rather fight Shamrock.