A compressor section for a gas turbine engine, comprising: a housing with a shroud surface having a circumferential groove therein, the shroud surface further having a plurality of stator vanes extending radially inward therefrom to vane tips; a first annular insert seated within the circumferential groove, the annular insert formed of an abradable material and including a first annular body having a radially inner surface, and further including a first plurality of groove segments (306,306') formed in the radially inner surface; a rotor assembly (200,202,204) rotatably supported within the housing, the rotor assembly including a rotor hub, the rotor hub having an annular surface; a second annular insert disposed within the annular surface of the rotor hub adjacent the vane tips of the stator vanes, the second annular insert formed of an abradable material and including a second annular body having a radially outer surface, and further including a second plurality of groove segments (306,306') formed in the radially outer surface; and a plurality of rotor blades extending radially from the rotor hub and terminating at a blade tip spaced from the first annular insert by a tip gap and defining a non-constant clearance region (474a,474b) between a first position at a leading edge on the rotor blade and a second position having a minimum tip gap clearance downstream of the first position in an aft axial fluid flow direction; wherein: the rotor blades generate an aft axial fluid flow in the housing, the first plurality of groove segments are formed in the first annular insert in the non-constant clearance region for resisting a reverse axial fluid flow through the tip gap when the compressor section is operated at near stall conditions, the first plurality of groove segments terminate at a rear groove segment in the aft axial fluid direction, and the rear groove segment is upstream of the minimum tip gap clearance. a housing with a shroud surface having a circumferential groove therein, the shroud surface further having a plurality of stator vanes extending radially inward therefrom to vane tips; a first annular insert seated within the circumferential groove, the annular insert formed of an abradable material and including a first annular body having a radially inner surface, and further including a first plurality of groove segments (306,306') formed in the radially inner surface; a rotor assembly (200,202,204) rotatably supported within the housing, the rotor assembly including a rotor hub, the rotor hub having an annular surface; a second annular insert disposed within the annular surface of the rotor hub adjacent the vane tips of the stator vanes, the second annular insert formed of an abradable material and including a second annular body having a radially outer surface, and further including a second plurality of groove segments (306,306') formed in the radially outer surface; and a plurality of rotor blades extending radially from the rotor hub and terminating at a blade tip spaced from the first annular insert by a tip gap and defining a non-constant clearance region (474a,474b) between a first position at a leading edge on the rotor blade and a second position having a minimum tip gap clearance downstream of the first position in an aft axial fluid flow direction; wherein: the rotor blades generate an aft axial fluid flow in the housing, the first plurality of groove segments are formed in the first annular insert in the non-constant clearance region for resisting a reverse axial fluid flow through the tip gap when the compressor section is operated at near stall conditions, the first plurality of groove segments terminate at a rear groove segment in the aft axial fluid direction, and the rear groove segment is upstream of the minimum tip gap clearance. the rotor blades generate an aft axial fluid flow in the housing, the first plurality of groove segments are formed in the first annular insert in the non-constant clearance region for resisting a reverse axial fluid flow through the tip gap when the compressor section is operated at near stall conditions, the first plurality of groove segments terminate at a rear groove segment in the aft axial fluid direction, and the rear groove segment is upstream of the minimum tip gap clearance.