The striker suffered the problem in the second half.
Warne has until next Thursday to bring new players in from other clubs.
The Ipswich loan striker has impressed in his early Rotherham career
The Millers boss was unhappy with his back four at Peterborough
Rotherham are on the verge of signing another defender.
The Millers are interested in signing the young Wednesday striker.
A rundown on Rotherham’s foray back into the Football League Trophy.
Paul Warne was a style icon at New York Stadium on Saturday.
Rotherham 5 Southend 0.
The Stevenage striker will not be coming to New York Stadium.