  We show that the Frenkel-Gross connection on $\mathbb{G}_m$ is physically
rigid as $\check{G}$-connection, thus confirming the de Rham version of a
conjecture of Heinloth-Ng\^o-Yun. The proof is based on the construction of the
Hecke eigensheaf of a connection with only generic oper structure, using the
localization of Weyl modules.
