Aberdeen drew against Rangers on Tuesday, but a win over Celtic on Sunday will see them end up as Scottish Premiership runners-up.
Aberdeen clinched a move for former Rangers defender Dominic Ball on deadline day.
The Tottenham Hotspur defender joined a League One club on loan.
Nottingham Forest manager Mark Warburton is known to be a big fan of Rotherham United's Dominic Ball.
Glasgow Rangers will know the quality of the players they bring to Ibrox this summer will be crucial for their chances of closing the gap.
Dominic Ball was part of the Glasgow Rangers side that won the second tier title and reached the Scottish Cup final before he left Ibrox in the summer.
Dominic Ball spent one season at loan at Ibrox, but has struggled since leaving Glasgow Rangers last summer.
Tottenham Hotspur's Luke McGee and Rotherham's Dominic Ball are both on loan at Peterborough United until the end of the season.
Former Glasgow Rangers loanee Dominic Ball has joined Peterborough United on loan.
Rangers missed out on Dominic Ball in the summer, but could they get a second chance?