The aggressive application of scalar replacement to array references substantially reduces the number of memory operations at the expense of a possibly very large number of registers. In this paper we describe a register allocation algorithm that assigns registers to scalar replaced array references along the critical paths of a computation, in many cases exploiting the opportunity for concurrent memory accesses. Experimental results, for a set of image/signal processing code kernels, reveal that the proposed algorithm leads to a substantial reduction of the number of execution cycles for the corresponding hardware implementation on a contemporary Field-Programmable-Gate-Array (FPGA) when compared to other greedy allocation algorithms, in some cases, using even fewer number of registers.