The former Celtic manager said the financial gap between the Glasgow clubs and the English league has widened considerably since the early 2000s.

He believes the Scottish football giants can no longer match the financial clout of even lower-tier English clubs. Strachan said: "The bar has risen now.

"When you come down [to England] you’re not only jostling for positions with the rest of Great Britain: Wales, Ireland."

He suggested that both clubs would struggle in the Premier League. "A good Celtic, a good Rangers, you’re talking near the bottom," he added.

He also said that the growth of English football has created a financial battle that Celtic and Rangers cannot win. "They can’t compete with Championship teams. I know full well they go for players who are maybe League 1 in England.

"They can’t deal with the transfer fees, the money."

Despite the financial challenges, Strachan said he still finds Scottish football entertaining. He said: "The actual Scottish game to watch, though, is quite exciting. From mistakes you get shots, headers, tackles.

"It’s great to watch because of the excitement of it."

He pointed out that in the early 2000s, Celtic's wage bill was the fifth highest in Britain. However, this is no longer the case, with both clubs now unable to compete financially with even Championship teams.

He said: "Competing with Birmingham for players, Celtic couldn’t do that."