Joe Wright's goal gave Rovers victory in their opening game of pre-season.
Grant McCann named entirely different sides for each half, giving each player as much game time as possible.
Rovers lined up with a back four of Danny Amos, Andy Butler, Tom Anderson and Niall Mason ahead of Ian Lawlor in goal.
Luke McCullough, Jacob Fletcher and Issam Ben Khemis took on midfield roles, with Alfie May playing ahead of Liam Mandeville and Alfie Beestin.
The heat had an effect on play, but Rovers controlled the ball well in the opening stages.
New manager McCann asked his side to play a high pressing game, giving Alfreton little time on the ball.
Home defender Martin Riley got in a key header to intercept a cross after five minutes, with a shot from May blocked 10 minutes later
The home side showed they should not be underestimated when Ben Khemis had to be alert to intercept a dangerous cross from Craig King.
Mandeville went close after 22 minutes before a drinks break, and Rovers picked up where they left off after the pause.
Ben Khemis found himself with space outside the area and curled a left-footed effort which bounced back off a post. Mandeville followed up, but his header went wide.
King curled wide again for the hosts, before they made their first change with Tom Denton coming on for Danny Clarke with half an hour on the clock.
The home side enjoyed their best chance of the half three minutes before the break when left-back James Clifton fizzed a low effort just wide.
Rovers changed all 11 players for the second period, with Marko Marosi, Mitchell Lund, Joe Wright, Tyler Garratt, Danny Andrew, Matty Blair, Cody Prior, Ben Whiteman, Alex Kiwomya, John Marquis and Max Watters coming on. The home side also made eight changes of their own, five of which were trialists.
Rovers again started brightly with some real intent, with Garratt unable to steer his effort from an Andrew corner on target in the opening minutes of the second period.
Rovers went ahead 15 minutes into the second period after some good offensive work from centre-backs Garratt and Wright.
The latter calmly slotted the ball past Tom Nicholson, who came on in goal for the home side at the break, to open the scoring.
Kiwomya and Marquis combined to cause the home defence plenty of problems, with one particular break from them ending with a scramble to force the ball wide at the near post under pressure from the Rovers' No.9.
But, with the heat taking its toll as the second period progressed, chances were at a premium.
Watters was pulled back for an offside flag after being played through in the closing stages, but in the end came away with victory, a clean sheet and important game time to build up fitness in preparation for the season opener at Southend United on Saturday August 4.