  V921 Scorpii is a close binary system (separation 0.025") showing the
B[e]-phenomenon. The system is surrounded by an enigmatic bipolar nebula, which
might have been shaped by episodic mass-loss events, possibly triggered by
dynamical interactions between the companion and the circumprimary disk (Kraus
et al. 2012a). In this paper, we investigate the spatial structure and
kinematics of the circumprimary disk, with the aim to obtain new insights into
the still strongly debated evolutionary stage. For this purpose, we combine,
for the first time, infrared spectro-interferometry (VLTI/AMBER, R=12,000) and
spectro-astrometry (VLT/CRIRES, R=100,000), which allows us to study the
AU-scale distribution of circumstellar gas and dust with an unprecedented
velocity resolution of 3 km*s^-1. Using a model-independent photocenter
analysis technique, we find that the Br-gamma-line emission rotates in the same
plane as the dust disk. We can reproduce the wavelength-differential
visibilities and phases and the double-peaked line profile using a
Keplerian-rotating disk model. The derived mass of the central star is
5.4+/-0.4 M_sun*(d/1150 pc), which is considerably lower than expected from the
spectral classification, suggesting that V921 Sco might be more distant (d
approx 2kpc) than commonly assumed. Using the geometric information provided by
our Br-gamma spectro-interferometric data and Paschen, Brackett, and Pfund line
decrement measurements in 61 hydrogen recombination line transitions, we derive
the density of the line-emitting gas (N_e=2...6*10^19 m^-3). Given that our
measurements can be reproduced with a Keplerian velocity field without
outflowing velocity component and the non-detection of age-indicating
spectroscopic diagnostics, our study provides new evidence for the
pre-main-sequence nature of V921 Sco.
