HUGH MACDONALD and MARTIN GREIG

Stephen McManus v Luca Toni

Arguably the biggest test of the Celtic captain's career. Standing strong at the heart of the Parkhead defence against AC Milan last month at Celtic Park will have provided the 25-year-old with a massive confidence boost ahead of today's meeting with the Azzurri.

McManus tackles with terrier ferocity and reads the game better than most but, occasionally, can appear susceptible in the air. In that area, the Italian striker will prove a formidable opponent.

At 6ft 4in, 30-year-old Toni is capable of waging an aerial war on teams. Against Scotland in Bari in March, he proved the difference between the teams. Italy's first goal that evening stemmed from McManus' foul on Toni after 11 minutes. Massimo Oddo flighted the ball into the box and Toni rose unmarked to score from 10 yards.

Twenty minutes from the end, Toni added another, plunging a downward header past Craig Gordon from a Mauro Camoranesi cross that dropped over David Weir.

Both McManus and Weir know they will be in for a torrid evening and their ability to physically dominate Toni throughout the contest could hold the key to keeping a clean sheet and achieving a positive result.

Scott Brown v Andrea Pirlo

This is the clash of opposites. Andrea Pirlo is the quarter-back of Italian football. His game is based on precision, possession and the ability to see the killer pass and he is central to everything Italy will attempt to do.

Pirlo will protect the back four and take the ball from central and wide positions to push his side forward. He is also dangerous in the final third, particularly from free-kicks and will let the ball do the work.

Brown, in contrast, is the hyperactive midfielder. He passes short, and runs long. McLeish may decide that Brown is the ideal man to harry Pirlo, especially when the Italian is in his own half. The AC Milan player relishes the space he is afforded by teams who sit back and do not press the ball.

Italy, of course, only need a draw and Pirlo will be content merely to retain possession. Brown will be central to Scotland's ambition of introducing pace and a degree of frenetic uncertainty to the match. This will be the most intriguing of contrasts and the most important of duels.

Gary Naysmith v Mauro Camoranesi

There have been suggestions that Camoranesi could be replaced by Vincenzo Iaquinta but the same battle lines will be drawn.

The names will be changed but the plot remains the same. This is the case of a full-back who has been struggling facing a wide man who is charged with getting beyond the defence.

Naysmith claims he is fully fit for the first time in recent memory but he has been embarrassed recently in a Scotland shirt by players with pace.

The Sheffield United full-back, however, has a grim determination and if he can secure his flank he could go forward to cause trouble at the other end.

The Italian gameplan relies on getting the ball to Luca Toni in the box. Naysmith will play a vital role if this strategy proves to be fruitless on the day.

Scotland's back four will be faced by three attackers on certain occasions. Naysmith cannot afford to lose his personal battle. If Italy score, the game may well be up. Naysmith has to find top form at Hampden today.

Alan Hutton v Gianluca Zambrotta

The battle of the athletes. Sparks will fly on the flank as Hutton and Zambrotta engage. The Barcelona left-back has recovered from a minor knee problem in time to face Scotland and set up a fascinating contest between the two.

Eighteen months ago this would have seemed like the ultimate mismatch, but Hutton has been immense in recent times, taking his game to new levels with his marauding style. Scotland were deprived of his services away to Georgia and missed him badly.

With the central midfield likely to be congested, both sides will look to the wings for creativity.

Hutton has delivered before. His swashbuckling run and slide-rule pass to James McFadden set up Scotland's clinching goal against Ukraine last month, and he has gained valuable experience in the Champions League with Rangers.

If there any deficiencies in his game, they concern his defensive abilities. The combination of Antonio Di Natale and Zambrotta will provide the ultimate test.

Lee McCulloch v Christian Panucci

Lee McCulloch's value as an attacker who can also defend could prove priceless. McCulloch will be stationed on the left of a five-man midfield and will be a key player in both penalty boxes.

At Italy's attacking set-pieces, Scotland will rely heavily on McCulloch's height and aerial abilities to repel the menace posed by Luca Toni et al.

Should Scotland come under a sustained period of Italian pressure, expect a series of long diagonal balls from Alan Hutton at right-back for McCulloch to try to knock on for the strikers. He also carries a goal threat of his own as his strike against Ukraine showed.

Christian Panucci is likely to win his 51st cap at right-back ahead of the injured Massimo Oddo. The 34 year-old's strength in the air should make for a compelling battle with McCulloch while he will also aim to get forward to support Mauro Camoranesi whenever possible.