Steven Naismith: 'Celtic need a challenger for the good of Scottish football'
Steven Naismith has warned that Scottish football will suffer should Celtic's supremacy continue unchecked.
Brendan Rodgers' side last week completed a domestic treble without losing a game, having won their sixth straight top-flight title by 30 points.
Naismith insists a credible challenger is required to enliven the game.
"Celtic won the league at a canter and the fan base, everything, will just die away if that continues," the Scotland player told BBC Scotland.
"If it's the same old every year, it gets boring and Scottish football needs strong teams at the top.
"When you think back to when Hearts were challenging Celtic and Rangers for the title [in 2005-06], it was so exciting and it gets many more fans involved."
Naismith insists a pivotal pre-season of recruitment lies ahead for Pedro Caixinha at the Norwich City striker's former club, Rangers.
The Ibrox outfit, who were promoted to the top flight last summer, finished third, 39 points adrift of Celtic and nine shy of runners-up Aberdeen.
"For Rangers to be that far behind Aberdeen and Celtic isn't acceptable," 30-year-old Naismith told BBC Scotland.
"As a club, this is a massive summer for them to get to the stage where they are competing again.
"To be back in Europe again is massive for them and for everyone in Scottish football. They need Rangers to be challenging."
"Hopefully, with the new manager, he gets what he wants and can put a good challenge together," said Naismith.
"The one thing you can say for Rangers is they have probably had the best support and, for a club that hasn't done too well, they've got that to fall back on.
"Hopefully they can turn it around and get back to being the successful team they always have been."
Naismith's former Ibrox and Scotland team-mate, Lee McCulloch, is the front-runner to become Kilmarnock manager on a permanent basis after a spell in interim charge.
Former Killie striker Naismith, who is in Gordon Strachan's squad for the 2018 World Cup qualifier against England on 10 June, says McCulloch did well in lifting the Ayrshire side clear of relegation trouble to finish eighth in the Premiership.
"It's been good for Lee McCulloch to get the opportunity to show his worth and he's grabbed it with both hands," Naismith added.
"It was a comfortable finish for Kilmarnock. I think it's his to turn down and, if it doesn't work out for him, I'm sure there will be other suitors out there for him.
"He's given them stability and the players have excelled for him.
"There have been some good results and some bad, but that comes with young players. He's done a fantastic job."