  Successful realization of polarized Drell-Yan physics program is one of the
main goals of the second stage of the COMPASS experiment. Drell-Yan
measurements with high energy (190 GeV/c) pion beam and transversely polarized
NH3 target have been initiated by a pilot-run in the October 2014 and will be
followed by 140 days of data taking in 2015. In the past twelve years COMPASS
experiment performed series of SIDIS measurements with high energy muon beam
and transversely polarized deuteron and proton targets. Results obtained for
Sivers effect and other target transverse spin dependent and unpolarized
azimuthal asymmetries in SIDIS serve as an important input for general
understanding of spin-structure of the nucleon and are being used in numerous
theoretical and phenomenological studies being carried out in the field of
transvers-spin physics. Measurement of the Sivers and all other azimuthal
effects in polarized Drell-Yan at COMPASS will reveal another side of the
spin-puzzle providing a link between SIDIS and Drell-Yan branches. This will be
a unique possibility to test universality and key-features of transverse
momentum dependent distribution functions (TMD PDFs) using essentially same
experimental setup and exploring same kinematic domain. In this review man
physics aspects of future COMPASS polarized Drell-Yan measurement of azimuthal
transverse spin asymmetries will be presented, giving a particular emphasis on
the link with very recent COMPASS results obtained for SIDIS transverse spin
asymmetries from four "Drell-Yan" $Q^2$-ranges.
