New Celtic bosss Brendan Rodgers says it is "disrespectful" to label the Scottish Premiership as a two-horse race between the champions and Rangers.
Rodgers, who hopes to sign "one or two" players, expects Aberdeen and Hearts, second and third last time, to improve.
"I think Aberdeen are going to be stronger again. They have signed some good players, as have Hearts," he said.
"The other teams will always fight to make it very difficult. There is no way it is only going to be two teams."
Having begun pre-season training this week, Rodgers says he is "taking his time" to "assess and analyse" the squad at his disposal before starting their Champions League qualifying campaign in three weeks.
The Hoops will travel to face either Flora Tallin of Estonia or Gibraltar side Lincoln Red Imps on 12/13 July, with the return leg at Parkhead the following week.
If successful, a further two-leg qualifying round awaits - either side of high-profile friendlies against Leicester and Barcelona - before the start of their title defence against Hearts on the weekend of 6/7 August.
"You have to remember these players are the current champions so they have earned the right for me to at least have a look at them," Rodgers told BBC Scotland.
"But I certainly think that having assessed the team over a number of games, there are one or two areas where there are maybe one or two we can bring in that can help.
"There is a lot of great work going on behind the scenes and the club has been terrific in terms of supporting what I want to add.
"In 12 weeks the Champions League group stages start and the most important thing for us is to be in it. That will be with the current players and hopefully one or two that can help them get there."
Old Firm rivalry 'won't affect Warburton friendship'
Rodgers renewed acquaintances on Tuesday with Rangers boss Mark Warburton, who worked in the youth set-up at Watford when Rodgers was manager from 2008-2009.
"We spoke a few weeks back and Mark is a good guy," he added.
"Whatever rivalry there is between clubs, it doesn't spread outside of the field in terms of our relationship.
"He did excellent work for me when I was at Watford and he has done very well in his own right as a manager, both at Brentford and up here at Rangers.
"It is going to be a competitive league this year. You want the best teams in it, and Rangers won their league last year and are in it.
"We are looking forward to the challenge of retaining the title. We will just concentrate on our own job and if we do that, we know we are in with a great chance of making it six in a row."