THIS was where things started to get serious this pre-season.
After the shadow-boxing of Evesham, Cirencester and Gloucester and the hard fitness work of Wales, this game, and the one on Saturday against Cardiff, will be the ones which will tell us most about the capabilities of our squad.
The diamond worked well on Saturday, but Mark Yates went back to 4-4-2 for this one, with a line-up of Scott Brown; Sido Jombati, Steve Elliott, Troy Brown, Craig Braham-Barrett; Jermaine McGlashan, Russ Penn, Matt Richards, Ashley Vincent; Jamie Cureton, Terry Gornell.
The main focus for me from that line-up would be to see how CBB would fare at left-back, the performances of the wide men and the Cureton-Gornell partnership in attack.
CBB did okay I felt. Nothing spectacular, he defended when he needed to in competent fashion and showed that he likes to get forward and looked to do so in support at every opportunity.
The wide men were fleeting in their impact. Both showed their pace on occasions and smoked past their full-backs, but only once in that first half, when Jermaine sent a great cross over which just evaded Cureton and Gornell, did they look really potent.
Jermaine led a counter-attack from a Coventry corner but was thwarted by good defending, but I felt that both struggled to get into the game for long periods.
Gornell worked hard, frequently dropping deep to try to link the play leaving Cureton to play off the shoulder of the defenders and use his movement to try and create space for others.
He had a couple of efforts on goal but in that first half we didn't really create much in the way of clear-cut efforts to test the Coventry goalkeeper.
Scott Brown was the busier goalkeeper, saving well from the lively Callum Wilson, via the post, and he and the experienced Leon Clarke gave Elliott and Troy Brown plenty to think about.
I have no concerns about that partnership going forward. They seem to have settled in well alongside each other, and if anything Brown has looked the more secure of the two.
He is not the tallest, but has a good spring on him and looks comfortable on the ball, and is a more than adequate League Two centre-back.
I felt the weak link in the back four was Sido, who looked very shaky, and will be definitely looking over his shoulder at Keith Lowe and fearing for his place in the side.
I wasn't overly convinced with the 4-4-2 as it doesn't afford much protection to the back four, as was shown when Clarke had too much time to pick his spot for Coventry's opening goal.
The starting side lasted an hour, then we gradually saw changes introduced, with Lowe, Billy Jones, Sam Deering, Byron Harrison, Jason Taylor, Zack Kotwica and triallist George Bowerman coming on at regular intervals.
Some of the new arrivals made better impressions than others, with Jones, Deering and young Kotwica the pick of them.
CBB will definitely give competition to Jones, but as it stands now I would see Billy starting the season, as he just seems to have that bit more composure and better distribution, but it will be interesting to see how that one pans out.
Deering has, I feel, been the best overall pre-season performer and is putting his hand up to be a regular in the first 11. That wouldn't be part of a two-man central midfield, or in a wide role - he has to either play off a front man or at the top of the diamond.
As for Kotwica, we need to guard against building the kid up too quickly. Remember when Marley Watkins came along, and when Theo Lewis scored as a 16-year-old against Southampton.
We thought this is it - the next best thing. One is now in Inverness, the other in Salisbury, so we must be careful, and not expect too much too soon.
When he came on, he was up against Cyrus Christie, and didn't get anywhere, and it was his error which allowed Christie to run through and score the second goal.
But when he went off, he had a field day against the full-back and it was noticeable that whenever the ball was played over the top, it was directed towards him, rather than out to Jermaine on the other side.
He showed good awareness to anticipate a piece of chest control and lay-off from Harrison, forcing the keeper into a save, and got a couple of crosses over, one of which was nearly finished off by Bowerman.
In his 25-minute cameo, I would say he was more of a threat from an attacking point of view than Vincent and McGlashan.
He needs work on his defensive responsibilities, but there is food for thought for Yates - while I cannot see him in the starting 11, but as is stands he may well be put on the bench early on.
Taylor and Lowe were their usual steady selves, and I thought Bowerman did well in the 12 minutes he had - and we need another forward. I wonder if the money could be found for that one... just might be worth a shout in my view.
I don't like to be over-critical, but he was, I'm afraid, sharper than Harrison, who set up that run for Kotwica but failed to take two half-chances for himself.
I know it's pre-season, but you want players going into the season with confidence and I think Byron's is very low at the moment.
One chance came from a McGlashan cross which was missed by the defender. Byron was in the right place but also missed it. The other was a shot which led to a rejected handball appeal.
There is a place up for grabs alongside Cureton, but at the moment I feel Byron is handing it to Terry Gornell on a plate rather than making him fight for it. He's got two more chances to turn it around.
There were plusses from last night, but also still a number of questions remain.
I think seven players - Scott Brown, Jones, Elliott, Troy Brown, Penn, Richards and Cureton - have pencilled themselves in for Burton. From what I have seen so far, I would play a diamond, and my other four would be Lowe at right-back, Taylor, Deering and Gornell.
I won't be at the Cardiff game as I am off to Scotland, but will be back for Kidderminster, when I think the riddles over that starting side may be answered - I think the eleven which emerges at Aggborough may get the nod...