The former Hearts pair joined up with the skeleton Light Blue squad at Murray Park today as the club awaits confirmation it will be granted membership of the SFA to play fixtures.
Black had previously agreed a deal to sign for the club before the SFL decided to admit Sevco Scotland Limited into the Irn-Bru Third Division for the forthcoming campaign. The player again stated his desire to play for the club in the bottom tier, if a satisfactory offer was tabled.
Beattie, meanwhile is without a club having left Hearts in the summer, winning the Scottish Cup with the Gorgie side during a short-term stay.
He became a cult-hero with the Tynecastle faithful for his last-minute penalty winner against former club Celtic in the Hampden
semi-final, but has not extended his stay in the capital, with a move back along the M8 now seemingly on the cards as he gets set to join his former Jambos team-mate Black in the Third Division.
The former Parkhead forward was on the books at Ibrox as a youngster, before going on to star for the Hoops and then West Brom, Preston North End, Crystal Palace, Sheffield United, Swansea City and Watford.
A decision is expected shortly from the SFA over whether to transfer Rangers' membership to Charles Green's company, with talks ongoing between the two parties.
McCoist has a major rebuilding job on his hands this summer after being left with just a handful of players, with the Gers set to start their campaign at Brechin City on Sunday in the Ramsdens Cup.