Former Celtic striker Craig Beattie has questioned whether the defending Premiership champions have "the bottle" needed to win the title if it goes down to the wire with Old Firm rivals Rangers.
Celtic and Rangers are currently level on points at the top of the league with only goal difference separating the two sides, who next meet in the Scottish League Cup final on December 8.
Celtic have dominated Scottish football in recent years, having won the Premiership title every season since the 2011-12 campaign, but Beattie believes their nerve could be tested if Rangers maintain their challenge under Steven Gerrard.
He said: "I discussed this yesterday with a very well-known journalist, who said 'It will be interesting to see if Rangers have got the bottle with three or four games to go... if they're in contention, will they have the bottle to stand up to potentially winning the league?'
"I flipped the question on him and said 'How do we know that Celtic have got the bottle?', because with three or four games to go, nobody has been challenging them of late.
"I get what he is saying from a Rangers perspective but from a Celtic perspective, they've been runaway winners for however many years now.
"So how will they cope with three or four games to go?"
Celtic beat Rangers in the first Old Firm game of the season in September, with Odsonne Edouard and Jonny Hayes scoring in a 2-0 win at Ibrox.
Beattie believes the remaining Old Firm league games will have a major bearing on the destination of the Premiership title.
He said: "The Rangers-Celtic matches, the head-to-heads are going to be vital. The first one Celtic won comfortably at Ibrox. Steven Gerrard got his tactics all wrong.
"He tried to snuff out Celtic's midfield, which is the strongest part of their team, but he played too many midfielders, there was no width to it.
"There were untried defenders in the Celtic team that weren't tested that day.
"If he had that match again, I think his selection would be different. I'm assuming he'll have learned from that, he's probably watched that back 10 times or more.
"If Steven Gerrard gets his tactics spot on, then I think the Rangers-Celtic matches will be pivotal."