He has also revealed that there could be another new addition drafted into the Ibrox ranks before the weekend.
Mohsni is considered to be a priority at present, with Gers boss Ally McCoist having expressed a desire to see a man who has been on trial at the club handed permanent terms.
Mather is confident an agreement can be reached with the free agent and insists the board are doing all they can to ensure the squad is as strong as possible for the 2013/14 campaign.
He told the Daily Record: "It's no secret that Alistair quite likes the trialist and the reports I'm getting back are positive. So if we can come to an agreement I think there can be a positive outcome.
"I'm happy to stand by the signings we've made. They'll allow us to have a better start to the season.
"The biggest predicament with Mohsni isn't the player. There has been a lot of speculation because he is a trialist.
"He's here playing in games and in the public eye. But there are another couple of faces we're looking at as well and that was one of the things Alistair and I were discussing on Tuesday night."
Mather added on reports suggesting Rangers could look at bringing Kenny Miller back to the club: "There's a balance in the players we have signed. (Jon) Daly is an older head while Nicky Clark is younger.
"But there's a possibility some players could move on and that might influence our requirements.
"Something could happen regarding a new signing by Friday, but agents do make things interesting."