  Recently, a theoretical study [Li {\it et al.},~npj Quantum Materials 6, 36
(2021)] investigated a model of a disordered $d$-wave superconductor, and
reported local time-reversal symmetry breaking current loops for sufficiently
high disorder levels. Since the pure $d$-wave superconducting state does not
break time-reversal symmetry, it is surprising that such persistent currents
arise purely from nonmagnetic disorder. Here we perform a detailed theoretical
investigation of such disorder-induced orbital currents, and show that the
occurrence of the currents can be traced to local extended $s$-wave pairing. We
discuss the energetics leading to regions of $s\pm id$ order, which support
spontaneous local currents in the presence of inhomogeneous density
modulations.
