The young winger appears to have recovered from back and hamstring injuries which have plagued him all season and is looking to complete the clubs first double in six years by taking out the Scottish Premier League and Scottish Cup.
"If we go into the game on Sunday knowing that if we win, we win the league then that will be good for us," Forrest said.
"Whichever way it happens, we're not bothered. We just want to win the league as quick as we can.
"The chance to win the league and do the Double is still a big deal for us.
"Celtic have not done it for six years now, so that would be a big achievement if we could do it this year."