I've always liked Morrow, more than most, and still think he could be a solid 3rd pairing puck-moving D-man even if he doesn't put up big numbers.
That being said, he's played 6 games of NHL hockey since December 4th, and in addition to 3 games in Providence during his conditioning stint, that's a total of 9 games in the last 130 days as of next Wednesday.
No way can I justify tossing him into a playoff game at this stage unless the Bruins are absolutely desperate.
As far as left-shot D-men go, he's behind Cross, Gryz, and O'Gara in these eyes because he simply hasn't played enough, even if one could argue he's the superior player.
And if it's to add a 3rd pairing partner for Colin Miller, Cross to me is the best option based on his age, experience, and performance in Providence.