LOANEES Andre Wisdom, Patrick Bamford, George Thorne and Zak Whitbread will be available for the play offs should Derby County be involved.
The Rams are odds-on for a top-six finish for the first time in seven years since winning promotion in 2006-07.
They currently occupy fourth place on 69 points with seven games left to play, and the loan signings have played an important role.
The loans of Bamford and Thorne run to May 31.
Wisdom and Whitbread are contracted to stay with the Rams to May 3 but their stays will be extended automatically for the play offs.
First-team coach Paul Simpson has praised the impact made by the loan signings.
“They have been excellent,” he said.
“We are in a position we didn’t expect to be in.
“We knew we were coming into a good football club with a good group of players but it has been superb the way it has gone, and the loan signings have made a big contribution in that.”
Wisdom has been ever-present at right back since arriving from Liverpool in October and Bamford has scored seven goals in 15 appearances following his move from Chelsea in January.
Thorne has impressed in the last three games after having to wait seven weeks for his debut.
Whitbread is providing back up to the central defensive pair of Richard Keogh and Jake Buxton.
He started three consecutive matches when he signed from Leicester City at the end of September before he picked up an injury. He has been an unused substitute since.