Injector seal replacement - 87 5KS

[Dave C.]

Trying to replace injector seals on an 87 5KS, one of the plastic shrouds
cracked and a piece of it fell down into the head... on the injector at the
front of the engine.

Will damage result if I leave it in there and drive the car?  

Are there any tricks I might try to fish the piece out without removing the
intake manifold?

Any advice would be appreciated.
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Dave C.