Contrast blush (CB) is an area with a density higher than the organ parenchyma in the arterial phase of contrast-enhanced computed tomography (CT). CB may be a sign of contrast medium extravasation, pseudoaneurysm, arteriovenous fistula, or other conditions; however, the indications for treatment remain unclear. Nevertheless, CB could be used to indicate a fatal scenario, such as delayed splenic rupture. Here, we present two multiple-injury cases of fatal delayed splenic rupture following the nonoperative management of a minor splenic injury. In both cases, despite morphological CT findings being minor on admission, CB was observed, and both patients could not rest owing to factors such as older age, a head injury, and drunkenness. Furthermore, in the CB case that indicated pseudoaneurysm, delayed splenic rupture occurred much earlier after the injury compared to the other case without the possibility of pseudoaneurysm. In conclusion, we recommend transcatheter arterial embolization be urgently performed in a case wherein the presence of a pseudoaneurysm is highly probable and factors such as multiple injuries and inability to rest are involved.