Dwight Yorke's signing looks set to trigger the departure of fellow countryman Stern John from Blues.
Leeds United and Coventry City are battling out to sign John for a fee in the region of £250,000.
John, 27, began the season as fourth-choice striker and Yorke's arrival from Blackburn Rovers appears to have pushed him further down the pecking order.
Both Leeds and Coventry have contacted Blues about John, whose contract is due to expire this summer.
John, a hero of the play-off promotion due to his winner at Millwall that took Blues into the final, has become frustrated at his lack of opportunity.
He has made three substitute appearances so far this season and any move won't be sealed until later in the week as he is away on international duty.
John scored the winner and made the other in Trinidad & Tobago's 2-1 defeat of St Kitts & Nevis on Saturday in a 2006 World Cup semi-final round qualifier. The Soca Warriors play Mexico at home on Wednesday.