The Australian MRI-Linac system has a split magnet with wide opening, which offers treatment flexibility with different patient positioning. However, the versatile patient setup and individual physique differences also lead to uncertainty for specific absorption rate (SAR) management. In particular, a standing patient may have body regions close to radiofrequency (RF) coil rungs, which may lead to high local SAR. In this work, numerical simulations were employed to investigate the SAR distribution while a human model was in different treatment positions and thus give safety management suggestions. A standard whole-body RF coil was also simulated as a reference.