Celtics' Kristaps Porzingis (calf) focused on playoff return

The top-seeded Boston Celtics will open the Eastern Conference semifinals on Tuesday without center Kristaps Porzingis, who vowed to recover from a calf injury "at a historic rate." Porzingis was diagnosed with a right soleus strain, which he sustained in the second quarter of Game 4 of Boston's first-round series against the Miami Heat.