Aberdeen manager Craig Brown admits trialist Rory Fallon will have to make a big impact at Pittodrie if he is to win a contract.
The New Zealand striker is training with the Dons but Brown would have to persuade the board to exceed their budget in order to sign him.
The 29-year-old played with Kari Arnason at Plymouth and left Yeovil before the transfer window closed after spending a month at the League One club.
Brown, whose team face Hibernian at Easter Road on Sunday, said: "He is a friend of Kari Arnason and we are giving him a training venue.
"He is a nice, big chap who is visiting a friend and obviously he is out of contract and I am interested to see how he shapes up.
"We are not going to make a decision right now because I can't go to the board with another player and another player and another player.
"We have got to be sure if we are to go to the board as we are at our budget maximum already. I am reluctant to ask for dispensation unless we are absolutely sure."