A tracked undercarriage roller assembly (17) comprises a roller body (18) having a through cavity (19) delimited by a radially inner surface (20), a shaft (22) inserted into the through cavity (19) of the roller body (18), a bushing (32) extending from a first axial end (32a) to a second axial end (32b) and radially interposed between the roller body (18) and the shaft (22), an annular chamber (34) at least partially filled with a lubricant and radially interposed between the shaft (22) and the bushing (32), a housing seat (37) obtained in the shaft (22) and comprising an inlet portion (39) facing an axial end surface (22d) of the shaft (22) and a measuring portion (40) placed inside the shaft (22) in an axial position comprised between the first axial end (32a) and the second axial end (32b) of the bushing (32), wherein the inlet portion (39) and the measuring portion (40) are each other aligned along an axial direction. A temperature transducer (41) is placed inside the housing seat (37) at the measuring portion (40), wherein the measuring portion (40) is placed at a radial distance from the bushing (32) between 8 millimetres and 50 millimetres.