  The aim of the space mission concept \theseus~is to continue to collect and
study the GRB events like \swift. It will allow us to study the early Universe.
Moreover, it will offer us to study with unprecedented sensitivity GRB emission
and to measure the redshift for the bursts with $z>5$. In this work, we
investigate the advantages of a optical and near-infrared telescope mounted on
the same satellite that is triggered by the GRB like \theseus/IRT. Afterwards,
we investigate the possible future developments in the GRB science, first for
the prompt phase and the for afterglow phase. We find that more than half of
the sources detected by \theseus, and will never be visible from a a
ground-based telescope. Moreover, only $\sim50\%$ of all observable sources are
visible within one hour, i.e. $<30\%$ of all \theseus~transient sources. A
higher number of observable sources can only be achieved with a network of
telescopes. \theseus~will permit to detect the NIR prompt phase of the longest
GRBs, increasing the number of events studied from gamma-rays to the
near-infrared from a handful of events studied up to now to $\gtrsim10$ GRBs
per year.
