Everton boss David Moyes is uncertain how Denis Stracqualursi, or fellow deadline-day arrival Royston Drenthe, will cope with the Premier League.
"We had Stracqualursi watched in Argentina last year and he was valued a lot more than we got him for - we took him for nothing," Moyes said.
"There weren't an awful lot of centre-forwards out there we could get and he became available to us at the last minute.
"In the end it was nearly worth the gamble to see how he does. We've done it before with loan signings; some have worked and some haven't.
"He has a good goalscoring record in Argentina but I'm not sure yet, we'll find out in time.
"He looks like he's got a good goalscoring record and looks like he can finish.
"But I do expect to play Cahill up front. He played up front against QPR so we will use him there.
"We have more options in midfield with the likes of Ross Barkley, Jack Rodwell, Marouane Fellaini, Leon Osman John Heitinga and Phil Neville.
"Where we don't have a lot of options is at centre-forward.
"I need to add Tim Cahill to the group up front to see if I can find a combination which can get me some goals and lead the line."
However, like Stracqualursi, the manager has questions about the left-sided player.
"We don't know enough yet about Royston," he added.
"We've not seen enough, although we have seen him in training.
"We'll give him a chance to work with Bainesy (Leighton Baines) as things go on.
"At the moment we are all looking; the supporters have had the same look as I've had and we will see what we can do.
"Everyone tells me he is a terrific player. There have been questions about him as a lad at times but I've found him fantastic in the week he's been here."