Morris is a patch. He's a stop gap until we get a high grade power forward or center to compete for a ring.
Honestly he'll probably start at PF, he'll rebound better here than Detroit simply because Drummond isn't around. He can stretch the floor too, he adds toughness, and a good contract.
The Celtics play a completely different game than the Pistons, he may excel with better pace.
He's a better scorer than Amir, has better and younger legs, he's about what I expected under the circumstances.