  The recently discovered $D_{s0}(2590)$ state by the LHCb collaboration was
regarded as the first excited state of $^1S_{0}$ charmed-strange meson. Its
mass is, however, lower than the Godfrey-Isgur quark model prediction by about
80 MeV. In this work, we take into account the $D^{\ast}K$ contribution to the
bare $c\bar{s}$ state, and show that the coupled-channel interaction induces an
88 MeV shift with respect to the conventional quark model $c\bar{s}$ state,
which is much closer to the experimental mass. Our study shows that in addition
to $S$-wave, $P$-wave coupled-channel interactions also play a role for hadrons
located close to two-hadron thresholds. We further scrutinize the unquenched
quark model results with a model independent approach. It is shown that the
two-body $D^*K$ decay width is proportional to the weight of the $D^*K$
component. To saturate the experimental total decay width with the $D^*K$
partial decay width we need a weight of about 60\% while to reproduce the
unquenched quark model result a weight of about 5\% is needed. Therefore, we
encourage future experimental studies on the two-body $D^*K$ partial decay of
$D_{s0}(2590)$.
