Celtic change wingers with Patrick Roberts on for James Forrest, while Rovers' Mark Ferry is replaced by Ross Gilmour.

The chances are coming thick and fast now as Jozo Simunovic almost steers a Callum McGregor shot on target with a clever flick, but Ross Dunlop is on the goal-line and is calmness personified as he strolls away to clear.

It's action-packed now as Dedryck Boyata crashes a header against the crossbar from six yards or so, connecting with Callum McGregor's neat cross.

Moussa Dembele answers my cry with a neat turn inside the box but the angle is too tight and Ross Stewart is able to beat away the Celtic striker's powerful shot.

Having made the mistake of getting up early to watch Andy Murray crash out of the Australian Open, I'm falling asleep here. Can someone liven this game up please?

Albion Rovers make their first change and it's Ryan Christie's "bestie" Calum Ferguson coming on to replace Ross Stewart.

Christie will be desperate to get on now to battle it out for flat-mate bragging rights.

Kieran Tierney has 60 minutes under his belt on his comeback from injury. He's been prominent in attack since there has been very little defending to do today.

Callum McGregor is his replacement for the final half hour.

Image source, SNS

Celtic full-back Cristian Gamboa spins on the ball to create room for a shot but his low drive is not firm enough to trouble Ross Stewart.

Rovers continue to hang in doggedly but it doesn't make for much of a spectacle. Celtic need to inject more pace into their play but it's difficult with such little room to work with behind the fell organised hosts, who are sitting so deep.

Celtic keep knocking on the door as Stuart Armstrong hammers a rising shot narrowly over the top.

Scott Sinclair hares in from the left and sends a skidding cut-back into a busy box where the ball is met by James Forrest. The midfielder digs out a first-time strike and keeper Ross Stewart is down smartly to save.

We're off again. Jozo Simunovic is on for Mikael Lustig as Celtic change things in defence. In truth, they could probably play without any defenders...

While most Scottish Cup rivals will not have met their opponents until walking out on to the pitch, Albion Rovers forward Calum Ferguson and Celtic midfielder Ryan Christie will probably have had breakfast together.

The 21-year-olds started their careers together in their home city of Inverness with Caledonian Thistle and are now flatmates after fate took them both to the west of Scotland but with contrasting fortunes.

Ferguson, a Canada Under-20 international, has had 17 outings this season for mid-table League One part-timers Rovers, scoring twice, but like Christie, who has made only seven appearances for the runaway Premiership leaders, is on the bench today.

Will we see the best friends on the pitch together later?

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Dare the League One side come out of their defensive shell in the second half or is that crazy talk?

I suspect the pattern will be much the same after the break, although the part-timers are likely to tire with the amount of chasing they are doing.

Richard Wilson
BBC Scotland at the Excelsior Stadium

Celtic are able to attack at will. Albion Rovers are defending deep, so the visitors are having to pick their way through. James Forrest and Scott Sinclair, whose goal was a brilliant piece of improvisation, are the liveliest figures in the final third for Celtic, while the two full-backs are spending most of their time high up the field. Fatigue will also become an opponent for Albion to counter after the break and the likelihood is that Celtic will take full advantage.

Image source, SNS

As we approach half time, the game continues to resemble a training exercise, with Rovers stubbornly hanging on and Celtic hogging the ball.

Scott Sinclair lashes an angled shot past Ross Stewart but is ruled offside when connecting with Mikael Lustig's clever ball over the top. Not much in it...

Celtic striker Leigh Griffiths takes to Twitter to explain his absence today...