  For a pure SU(2) Yang-Mills theory in 4D we revisit the spatial (3D),
ball-like region of radius $r_0$, in its bulk subject to the pressureless,
deconfining phase at $T_0=1.32\,T_c$ where $T_c$ denotes the critical
temperature for the onset of the deconfining-preconfining phase transition.
Such a region possesses of a finite energy density and represents the
self-intersection of a figure-eight shaped center-vortex loop if a BPS monopole
of core radius $\sim \frac{r_0}{52.4}$, isolated from its antimonopole by
repulsion externally invoked through a transient shift of (anti)caloron
holonomy (pair creation), is trapped therein. The entire soliton (vortex line
plus region of self-intersection of mass $m_0$ containing the monopole) can be
considered an excitation of the pressureless and energyless ground state of the
confining phase. Correcting an earlier estimate of $r_0$, we show that the
vortex-loop self-intersection region associates with the {\sl central part} of
a(n) (anti)caloron and that this region carries one unit of electric U(1)
charge via the (electric-magnetic dually interpreted) charge of the monopole.
The monopole core quantum vibrates at a thermodynamically determined frequency
$\omega_0$ and is unresolved. For a deconfining-phase plasma oscillation about
the zero-pressure background at $T=T_0$ we compute the lowest frequency
$\Omega_0$ within a {\sl neutral} and homogeneous spatial ball (no trapped
monopole) in dependence of its radius $R_0$. For $R_0=r_0$ a comparison of
$\Omega_0$ with $\omega_0$ reveals that the neutral plasma oscillates much
slower than the same plasma driven by the oscillation of a monopole core.
