The margin for error is suddenly getting thinner for Texas baseball. After dropping two of three against Tennessee in Knoxville, the Longhorns return home for their final SEC series of the regular season against Missouri needing a strong response. Texas is still firmly in the hunt for a top-eight national seed and remains tied for second place in the SEC. But another series loss — especially against the conference’s last-place team — would make things a lot more uncomfortable than Texas would prefer.  A series win would likely solidify Texas’ position as a regional host and keep the Longhorns comfortably inside the top-eight seed conversation. With a series loss, however, it’s possible a little more uncertainty could arise. And while Texas probably owns a strong enough résumé to survive it, the Longhorns would much rather remove all doubt now. Here’s what Texas needs to do this weekend to avoid a third SEC series loss. 1.…