阿兰：麦克林“必须首发”对阵巴西。

Scott Allan wants Kenny McLean (centre) and Lewis Ferguson (right) to protect the centre of defence [Getty Images]

Kenny McLean has "got to start alongside Lewis Ferguson" for Scotland against Brazil in their World Cup Group C decider tonight, according to former Celtic and Hibernian midfielder Scott Allan.

Norwich City's McLean made an impression with his passing when coming on as a substitute in the 1-0 defeat by Morocco.

And Allan believes keeping possession in midfield will be vital in the searing heat in Miami.

"It would play a factor if we don't at least keep the ball for at least some spells in the game," he told the BBC Scottish Football Podcast. "For me, Kenny MacLean's got to start alongside Lewis Ferguson.

"Lewis Ferguson, I think he's been a standout, certainly out of possession for Scotland in this tournament. Showed great energy levels, picked up the second balls."

Meanwhile, Allan thought McLean added "that bit of composure".

Allan, who predicted correctly Kieran Tierney would start on the wing against Morocco, this time suggests head coach Steve Clarke will stick with a four-man defence instead of reverting to a five.

He thought it worked "except for 70 seconds" when Morocco scored their winning goal.

"I would go 4-2-3-1 and then goes into a 4-5-1 - you flood the midfield," Allan said.

That would be important to put pressure on Casemiro, the ageing Manchester United midfielder who was careless in possession when put under pressure by Morocco.

Allan would also like to see Lawrence Shankland up front but added: "I think he might opt for [Lyndon] Dykes just because, if we are sitting in, he gives you that presence and he is the best at getting the nod down to John McGinn, Scott McTominay and Ben Gannon-Doak."