Another reference to The Tempest, Phlebas --
like Alonso -- has drowned. Phlebas is a combination of the Phoenician
Sailor and Mr. Eugenides. His redemption (rising from the dead,
rebirth, etc.) is still uncertain.
Eliot merges the sailor and Mr. Eugenides, the one-eyed merchant, to show
that the modern fertility god-- Phlebas-- is merely a businessman
interested in "profit and loss". Primitive fertility gods were thrown in
the water in the winter, hence the connection of Phlebas and fertility. If
Phlebas is not resurrected, the wasteland remains barren and the King infertile.
However, seeing as Phlebas has so far spent "the stages of his age and youth"
in the whirlpool, his chances of resurrection are slim.
The whirlpool, and later mention of the "wheel" you turn, are probably
connections to the medieval "Wheel of fortune" and the Buddhist wheel
of life. To reach Nirvana, one must leave the wheel, i.e. the whirlpool
which sucks you under.