Matsui (back) will throw a bullpen session Tuesday, AJ Cassavell of MLB.com reports.
Matsui developed some back spasms following his first appearance of the spring but has progressed since then and is ready to try things from the bump again. Padres manager Mike Shildt expressed optimism Tuesday that Matsui will have time to ramp up for Opening Day as long as he continues to trend in the right direction. Matsui fanned the side in his lone Cactus League appearance and is in the mix to close for San Diego.