Coverage: Tuesday: live commentary of Rangers v Hamilton on Radio Scotland Sportsound 810MW from 1810 and on BBC Sport website, including updates from other two matches. Wednesday: live coverage of Kilmarnock v Celtic on Sportscene, BBC One Scotland, 1930, on Radio Scotland Sportsound 810MW from 1810 and on BBC Sport website. Highlights of all quarter-finals available on BBC Sport website on Wednesday night
By Andy Campbell
Seven SPL teams and one First Division side take a break from league action this midweek to focus on the quarter-finals of the Co-operative Insurance Cup.
Here, BBC Sport profiles the four ties and casts an eye over the form book for each side.
Dundee United v Dunfermline (Tue)
United qualified for the last eight with a 2-0 home win over Airdrie and were most recently in action against St Mirren in the SPL.
A victory over the Buddies took Craig Levein's side's winning run to five.
The Tangerines reached the final of last year's tournament only to be beaten on penalties by Rangers.
Safe passage through to the semi-finals would no doubt get the United fans dreaming of going one step further in this year's competition, but visitors Dunfermline will be determined to prove their cup credentials by causing an upset.
The Pars have begun their second successive season in the First Division following relegation from the SPL in 2007.
Now bossed by former United player Jim McIntyre, the East End Park side are on a five-match unbeaten run and currently sit third in their division, three points behind leaders Queen of the South, with a game in hand.
Dunfermline's squad boasts a number of players with SPL experience, including Graham Bayne, Stephen Glass, Andy Kirk and Scott Wilson.
Team newsFalkirk v Inverness CT (Tue)
The Bairns have had an up-and-down start to their league season, often losing games where they should have at least drawn.
Falkirk have lost half of their matches so far this season but have picked up valuable cup wins over Raith Rovers and Queen of the South.
The scoring form of Steve Lovell and Scott Arfield was once again evident during Saturday's morale-boosting SPL win over Kilmarnock.
And if the Inverness defence are to successfully withstand the Falkirk attack, they will have to do so without the injured Phil McGuire.
The Highlanders are on a run of three straight defeats, the latest of which came at home to Motherwell on Saturday, despite taking the lead.
Inverness required extra-time to oust Morton in the last round and were taken to penalties by Arbroath in the second round.
But Craig Brewster's side will take heart from their victory at the Falkirk Stadium earlier this season.
Team newsRangers v Hamilton Accies (Tue)
Both sides meet for the second time in four days having played an SPL fixture at New Douglas Park on Saturday.
On that occasion, Hamilton were unfortunate not to go in at half-time in front as Rangers levelled before the break, going on to win 3-1.
The Ibrox club have stuttered recently with their first league defeat of the season at St Mirren earlier this month and a poor first-half performance against Accies.
Rangers were taken to extra-time by Partick Thistle in the last round with Walter Smith's side unconvincing on the night.
Accies reached the last eight stage after winning the first Lanarkshire derby of the season against Motherwell.
That 2-1 victory at Fir Park interrupted a run of SPL defeats which, after losing to Rangers, has stretched to five.
But Hamilton are no strangers to causing a cup upset at Ibrox, having famously won a Scottish Cup tie there in 1987.
Accies manager Billy Reid said: "We're looking forward to going to Ibrox for the first occasion for many a year and will meet the challenge head on."
Team newsKilmarnock v Celtic (Wed)
The relative league positions of both these sides probably makes this match the tie of the round.
The home side currently sit third in the SPL after an impressive start to the season that has included wins over Dundee United, Hearts, Hibernian and Motherwell.
Killie reached the quarter-finals after a 4-2 win over Aberdeen, a match in which all the goals came in the first half.
But Jim Jefferies' side went down 2-1 at home to Falkirk at the weekend and were beaten by Celtic in the league earlier this season.
Celtic's high-scoring start to the season continued on Saturday with a 4-2 win over Hibernian.
That victory was achieved without top scorer Georgios Samaras and fellow striker Jan Vennegoor of Hesselink, illustrating the depth in Gordon Strachan's squad.
A 4-0 home win over Livingston sent Celtic into the last eight and the SPL leaders have previously put four past Motherwell and Hamilton.
Team news~RS~q~RS~~RS~z~RS~24~RS~)