Colchester United were held to a draw in the opening game of the season at Carlisle United, with Mullins picking up a point in his first game in charge.
In a fairly even and end to end game, the home side had perhaps the better of the chances, forcing Shamal George into action a couple of times in the second half.
But the U's were not without their own chances, with Frank Nouble mis-hitting his best chance of the match, as well as Norman and Sears forcing Norman into a couple of good saves.
Hayden Mullins' first Colchester United side included four debutants, with Luke Chambers, Cole Skuse, Alan Judge and Cameron Coxe all making their first start for the club, with Freddie Sears making his second debut after returning.
The bench for the U's also included three new faces, with Turner and Jasper the loan signings, and youngster Gene Kennedy making his first matchday appearance for the side.
It was the home side who looked dangerous in the opening exchanges, spurred on by their crowd. But they were unable to test George in the first moments of the game, with Abrahams and former U's man Brennan Dickenson lifting efforts over the bar.
But it wasn't long before the U's were able to carve out a chance in the game, and it was perhaps the best so far. Frank Nouble's clever flick to Freddie Sears saw the latter cross back towards Nouble, who wasn't able to apply the finish.
It was turning into an end to end game, with the hosts going close just before the half hour mark. On the break, Brennan Dickenson crossed the ball to Abrahams who in turn helped it on to Mellish, only for his effort to be straight at George.
The U's 'keeper had a far more difficult save to make a minute later though, when he got a strong wrist to McDonald's header, pushing the ball around the post.
At the other end of the pitch, Tommy Smith attacked the ball from Alan Judge's free kick, but was unable to generate enough power on the effort, seeing it bounce into the grateful arms of Magnus Norman.
Just before the half time whistle blew and the two sides went to seek refuge from the rain in Cumbria, there was a duo of chances for Colchester United. Freddie Sears proved difficult to track as he twisted and turned in the area, only to find Norman with his effort.
And Norman was called into action again moments later when his athletic save prevented Alan Judge from netting the opener with a fine chest and volley.
The two teams headed for the dressing room with the score at 0-0.
With no changes to either side at the break, the U's came out in the second half much quicker than they had the first. No less than two minutes had passed when Freddie Sears had forced Magnus Norman into a save. From Wiredu's mis-hit shot the front man raced behind to fire an effort on goal.
The home side were growing into the game though, and had the best chance of the game for either side when Brennan Dickenson was racing free through the middle. A combination of pressure from Cole Skuse and Shamal George making himself big prevented the opener as the U's were let off.
Shamal George was frustrating the home fans further not long after with a brillant double save to deny Abrahams and Mellish. From almost point blank range the U's 'keeper pulled off two magnificent saves to ensure the home side didn't take the lead.
Tommy Smith had another good chance in front of goal to put his side ahead with ten minuted to go. From an Alan Judge corner kick, Smith rose hightest, but was unable to keep his header down, with the ball flying over the bar.
Hayden Mullins' first change of the game saw Freddie Sears withdrawn for Sylvester Jasper, and the man coming on made an instant impact. Becoming a handful for the home defence, Jasper quickly won a corner and proved his pace was a problem on the break.
Colchester United were unable to find a way through though in the final ten minutes, and picked up a well deserved point on the road on the opening day.
Next up for the U's is their Carabao Cup First Round tie against Championship side Birmingham City on Tuesday evening.
Carlisle United starting XI: Norman, Tanner, Armer, McDonald, Guy, Alessandra, Clough, Dickenson (Toure 85'), Mellish (Mampala 78'), Abrahams, Whelan.
Unused subs: Jensen, Riley, Charters, Feeney, Bell.
Colchester United starting XI: George, Clampin, Chambers, Smith, Wiredu, Skuse, Nouble, Judge, Sears (Jasper 82'), Eastman, Coxe.
Unused subs: Turner, Welch-Hayes, Chilvers, Kennedy, Tchamadeu, Tovide.