We summarize and discuss some of the available experimental and theoretical data important for understanding the role played by subsurface sites in dissociative chemisorption calculations for the H-2/Pd(111) system. Then we use a semi-empirical potential energy surface (PES) to model the interaction of a H-2 molecule impinging on a Pd(111) surface. The London-Eyring-Polanyi-Sato (LEPS) construction has been extended to make direct subsurface absorption possible. A two-dimensional wave packet calculation is used to find qualitative trends in the direct subsurface absorption and to reveal the time scales involved. We suggest that a partial in-plane relaxation occurs for the slowest incoming particles, thus resulting in a higher direct subsurface absorption probability for low energies.