Hybrid meat, a blend of plant and animal proteins, aims to mitigate the rising sustainability concerns associated with traditional processed meat products. Soy proteins have been widely used for a long time, at low concentrations, to improve the functionality of processed meat products. However, limited information exists regarding its use at elevated levels. This study assessed how different soy protein powders, at 0 (control), 33, 66, and 100%, impact the water holding and textural properties of lean chicken breast meat systems with 0, 40, and 80% added water. Soy protein isolates (SPI-A, B, C, and D) and soy protein concentrate (SPC) were hydrated to match the lean meat protein concentration. Batters were cooked in a water bath to 72 °C. Cooking loss and texture profile analysis (50% double compression) were measured. T2 relaxation time was assessed using a 20-MHz NMR spectrometer. Light micrographs of cooked batters were taken. A three-factor factorial design with three independent replications was employed. In the 0% added water system, the SPI-D (33% and 66%) caused subtle (but not significant) cooking losses, while others did not. Regarding hardness, the SPI-D and SPC showed the largest significant decrease and increase, respectively, as inclusion rose from 33% to 66%. The hardness of 66% SPI-A was similar to the control. In the 40% added water system, at 66% soy, the SPI-A and SPC reduced cooking loss, but SPI-D increased it. The hardness of soy protein treatments followed a similar trend to the 0% water system, with the exception that SPC’s hardness values decreased as inclusion increased. Yet, the SPC was still harder than the control. In the 80% water system, SPI-D had similar cooking loss to control, while other soy proteins reduced it as inclusion rose. At 66% soy, the SPI-A, B, C, and SPC had comparable hardness to the control, while the SPI-D disrupted meat gel. At 100%, all soy proteins failed to form a self- supporting gel. Micrographs and NMR T2 profiles supported the cooking loss and hardness measurements.