Best guess would be that he died from wounds received during this engagement:

"About the last of February 1863, while on this outpost duty, the 8th Confederate suffered its first serious reverse. About 80 officers and men, Lieut. Col. Prather commanding, were posted at the little hamlet called Rover, 10 miles in advance of Shelbyville, the nearest supporting force. The remainder of the regiment was either on other roads or on scouting duty. Our videttes were driven in closely followed by a brigade of cavalry consisting of the 4th Regulars, 4th Michigan, 3rd Kentucky and 7th Pennsylvania. They came down the pike in column at a charge with flanking battalions in line on either flank in the open fields. Colonel Prather formed his men in column on the pike between high staked-and-ridered cedar fences on either side. We met the enemy’s column with a counter charge and after a glorious but ineffectual, hand-to-hand combat with pistols and sabres, were simply overwhelmed. Captains Moore, Thompson and Miller yielded under sabre strokes and with some twenty-five of the men were captured, carried to Eaglesville and were safely guarded that night by a division of infantry, two batteries of artillery and the brigade of cavalry under General Minty that had comprised the whole expedition on our pike. Next day the prisoners, nearly all with sabre-cuts, were escorted to Murfreesboro by a detachment of 4th Michigan, the 8th Confederate’s old acquaintance at Blackland, Miss., and its fated opponent on almost every field until the 8th Confederate wiped out the score of Rover by the drubbing given it near Kingston, Ga., in May 1864, when it captured its Major Grant and more of its men than we lost at Rover. The captives at Rover were sent to various northern prisons and were on boats for exchange lying at Fortress Monroe, listening to the roar of guns up the Rappahanock where Lee and Jackson were knocking "Fighting Joe Hooker" out of his arm-chair in the Chancellor house and giving a very black eye to "the finest army on this planet" Source: George Knox Miller

However, there is also a possibility that he was wounded at Murfreesboro, or some of the related engagements following that event (i.e. Mills Creek, Raid on Nashville, Harpeth Shoals naval engagements, Raid on Ashland). Soldiers died from wounds received at Murfreesboro well into the summer of 1863.