Head coach Chris Beech took charge of his first game with the Blues on Saturday afternoon as they went up against Forest Green Rovers in the second round of this season's Emirates FA Cup competition.
Teenager Jarrad Branthwaite was missing through illness, and that meant a call-up to the starting eleven for Aaron Hayden.
Completing the trio of changes was Byron Webster for Jon Mellish and Stefan Scougall for Harry McKirdy.
United went with a 4-1-2-3 formation, with Carroll sat in front of the back four, and with Olomola given the central striking role.
It was a bright start from the visitors, as they pressed with Scougall and Olomola on the left flank, but things stayed tight as both teams defended well.
But disaster struck for the Blues on 11 minutes when the first meaningful attack of the day brought a cross from Bernard. Gethin Jones got there first, but the ball looped high into the air before dropping onto the bar. Collin tried to push it away but Collins steamed in to head the dropping ball into the net.
Rovers came again when Bernard overlapped and called for the ball. His cross was met by a leap from Stevens but he couldn't keep his 10-yard header on target.
Carlisle were a whisker away from drawing level on 18 minutes when Carroll came away with the ball in midfield. He used Loft, who needed just one touch before picking out Olomola on the edge of the area. The forward teased his marker before sending a low drive through his legs, and Wollacott was relieved to see it creep past his upright.
More good football from the visitors saw Thomas spin his man before releasing Olomola. He was forced wide, but the cut back was perfect for Mike Jones to strike. He seemed to hesitate but his 18-yard effort lacked the power it needed to really test the target.
It was United who looked the more likely to get the second goal of the day but they wasted another great opportunity when Thomas worked space for Iredale to cross. Olomola made a near post run but he got his bearings wrong and a heavy touch saw him send his volley into the stands.
But Forest Green found a way through on 35 minutes when Aitchison slipped the ball past Webster, with options either side. Shephard was beside him, and a neat lay-off invited the right back to shoot. Adam Collin pulled off a superb save, to push the thunderbolt onto the bar, and blue shirts were back in numbers to complete the clearance as it fell onto the sticky surface.
United got their goal on 40 minutes when Forest Green dithered when they should have cleared. Iredale robbed it and gave it to Thomas who was in acres of space. He took his man on, fed the ball onto his right foot and left Wollacott with no chance as he crunched it into the net via the underside of the bar.
Stopper Adam Collin was in action again when he dived at the feet of Matt Stevens to prevent him from converting a Shephard cross. The punch went as far as Aitchison, but his air shot took the pressure off the stretched defence.
Thomas was the hero at the other end in time added on for the period when he cleared a Stevens header from a Mills corner off the line, and the teams headed into the half time break with it all still to play for.
Aitchison rattled a volley wide just 25 seconds after the restart, and Carlisle had a moment when a Thomas corner was volleyed by Loft. The connection was untidy and Wollacott scooped it up easily.
Keeper Adam Collin showed his quality again as the second half battled to get going, when Collins twisted and turned his way into a shooting position. It took a wicked deflection but the stopper readjusted to make a fine block.
Rovers probed just after the hour, with Shephard sending one over the bar from wide, and Stevens wheeled away in disappointment when he skewed a shot into touch when it looked easier to test the nets.
But it was Carlisle who took the lead for the first time on the afternoon when Carroll sparked an attack after some wonderful play in midfield. His strength and poise released Hope, and his first-time delivery was met on the run by Thomas. Wollacott had no chance as a stinging volley bulged the net right in front of the away fans.
The lead was short-lived as the hosts whipped a set piece into the mix. It pinged around but Stevens kept his eye on it before toe-poking it towards the bottom corner. Gethin Jones stuck a boot out but his touch took it past a full length dive from Collin.
A late goalmouth scramble saw United block twice as Stevens and Rawson tried to finish off a pass from Collins, and Stevens was guilty of a terrible miss when he popped at free header straight at Collin.
Both sides closed the door inside their resepctive penalty areas and they'll have it all to do again in 10 days time for the right to take the third round place.
Forest Green Rovers - Collins (11), G Jones OG (78)
Carlisle United - Thomas (40, 76)
Forest Green Rovers - Adams (53)
Carlisle United - G Jones (20), Webster (29), Thomas (76)
Forest Green Rovers - Wollacott, Shephard, Bernard (Grubb 85), Rawson, Winchester, Stevens, Collins, Adams (Dawson 69), Kitching, Mills (c), Aitchison (Mondal 65). Subs - Thomas (gk), Morton, McGinley, Taylor.
Carlisle United - Collin (c) (gk), G Jones, Hayden, Webster, Iredale (Mellish 83), M Jones, C Carroll, Scougall, Thomas, Loft (Hope 59), Olomola (McKirdy 75). Subs - Gray (gk), Bridge, Knight-Percival, Sagaf.
Referee - Trevor Kettle
Assistant Referee 1 - Steven Plane
Assistant Referee 2 - Darren Wilding
Fourth Official - Mark Derrien
Attendance - 1,504 (228 away fans)