The Celtic goalkeeper has claimed that the league's heavy favourites are still facing a difficult season ahead despite the expulsion of their Old Firm rivals from the top flight
The Ibrox outfit are set to enter the Scottish Third Division, subject to the ratification of the Scottish Football Association, raising concerns that the SPL title race will be a foregone conclusion due to the annual dominance of the Old Firm clubs.
The two giants have retained the top two places in the league for all but one of the last 17 seasons, but Forster does not expect the rest of the SPL's teams to fail to mount a challenge.
"If you win the league you win the league, it is a fantastic opportunity for the other teams in the league to go for that second place or compete for the league," Forster told reporters.
"Realistically everyone should be setting out hoping they can win the league, if you don't think you can win the league you never will."
While Forster acknowledged that other teams will be determined to prove themselves against Celtic, the 24-year-old insisted the Bhoys will not let their guard drop.
"We will go out and be positive and play against whoever we play against," he said. "The league is important and it will mean as much winning it this time as winning it last year."