Central defender Ian Sharps was missing as he was taken ill before the game that saw Marc Joseph come in to replace him while Ryan Taylor came back in up front to the exclusion of Peter Holmes.
The Millers were first on to the attack with a Chris O'Grady cross but Wanderers soon replied with a free kick that was headed back across the area for Andy Warrington to collect.
Torres drove an effort over the bar as the home team kept up the pressure and after a fruitless corner they had another chance when McCracken's free kick was turned out for a corner.
McGleish sent Knight away but his shot was saved before the Millers got into the game more with O'Grady having a 20th minute shot saved.
A Marc Joseph free kick went out for a goal kick and then an Adrian Pettigrew cross was headed out. The loanee joined the attack again with another cross that brought no opening and a Pablo Mills long run saw him just put his intended pass to Ryan Taylor a little too hard.
Two home free kicks went straight to Warrington and from a long ball out of defence, McGleish fired only just wide. Then came the best effort of the first half on 39 minutes when O'Grady found Mark Hudson who pulled the ball back for Danny Harrison but his goalbound shot was blocked by Johnson.
Then O'Grady had a shot saved and in first half added time a 25 yarder from Harrison was saved. The second half started with a low cross from O'Grady being missed by the keeper but no one was able to take advantage before the home keeper caught a 48th minute Rotherham corner.
The deadlock was broken on 50 minute when Wanderers took the lead with McCracken heading home a Martin corner. The Millers made a couple of substitutions as they looked to get back on level terms with youngster Jamie Green making his debut and Graham Coughlan fired a 30 yarder straight at the keeper.
Two Rotherham corners brought no reward as Wycombe defended very deeply dropping back in numbers to leave just one man up front as they looked to protect their slender lead.
But they did break forward through Bloomfield to win a corner that was punched away by Warrington and then Holt fired wide to waste a good chance.
In the last few minutes Ryan Taylor saw a cross cleared and then as the game went into added time he almost grabbed an equaliser but his shot went just over the bar.
Wycombe: Fielding, Martin, Johnson, McCracken, Lennon, Woodman, Torres, Doherty, Holt, Knight (Bloomfield 64), McGleish (Sutton 90 + 2). Subs: Williamson, Palmer, Young.
Rotherham: Warrington; Tonge, Joseph, Coughlan, Pettigrew (Green 61); Harrison, Mills (Ross 78), Hudson; D. Holmes (Yates 52), O'Grady, Taylor. Subs: O'Donnell, P. Holmes.
Referee: Grant Hegley (Hertfordshire).
Attendance: 4,610 (325 away).
