Rotherham United are hoping to resurrect a trial for a German striker they have had training at the club.
The Millers, who failed in their attempts to sign any attacking players in the January transfer window, were hoping the unnamed frontman was going to play in the reserves clash on Tuesday.
However, they were unable to get the paperwork sorted in time as his most recent club was in Saudi Arabia and he has returned to Germany.
It is something they are planning to look at again when the administrative issue is resolved.
"He'll come back," Warne said. "Obviously, we tried to strengthen up top during the transfer window and came unstuck so we're now trying to go down another avenue and see if there is another option that can help us.
"If it works out, it will be a short-term deal to the end of the season.
“We were trying to get his paperwork sorted for him to play in the ressies game on Tuesday but unfortunately his international clearance didn't come through.
"It wasn't our fault. It was at the other end. His last club was in Saudi Arabia so the system hasn't been the quickest. Once the paperwork is sorted, he will come back over and we'll take another look at him.
"We looked at him in training for two days but I don't think you can really judge people in training. You need to see them in a proper game."
With Kyle Vassell possibly facing surgery on a groin problem that will not clear up and Jamie Proctor out for the season following hip surgery, the Millers only have Michael Smith by way of an out-and-out striker.
Warne is keen to bolster his options in attack should anything happen to the pivotal Smith.
The boss added: “Vass (Kyle Vassell) isn't 100 per cent and if something happened to Smudge (Michael Smith) I'd have to put my coaching hat on and make Semi (centre-half Ajayi) the best number nine of all time.
"We're always on a little bit of a knife-edge with Smudge. Luckily, he's built like granite so we should be okay."
The Millers take on Wigan in a huge Championship game at the AESSEAL New York Stadium on Saturday, hoping to move further away from the dropzone