  HQET is an effective theory for QCD with N_f light quarks and a massive
valence quark if the mass of the latter is much bigger than Lambda_QCD. As any
effective theory, HQET is predictive only when a set of parameters has been
determined through a process called matching. The non-perturbative matching
procedure including 1/m_b terms, developped by the ALPHA collaboration,
consists of 19 carefully chosen observables which are precisely computable in
lattice QCD as well as in lattice HQET. The matching conditions are then a set
of 19 equations which relate the QCD and HQET values of these observables. We
present a study of one-loop corrections to two generic matching observables
involving correlation function with an insertion of the A_0 operator. Our
results enable us to quantify the quality of the relevant observables in view
of the envisaged non-perturbative implementation of this matching procedure.
