Three goals in the space of eight minutes around the hour mark saw Wigan Athletic conclude their pre-season programme on a losing note and hand Steven Gerrard’s Rangers a victory that could and should have been even more emphatic.
The visitors had held their own for a relatively even opening 45 minutes, with neither goalkeeper really called upon for much inn the way of action.
But the withdrawal of centre-back Dan Burn at the break - with a worrying foot injury - appeared to have a disruptive effect on their defensive solidity.
Rangers started the second period like a house on fire and, just nine minutes in, Daniel Candeias’ cross was headed home by Alfredo Morelos.
Four minutes later it was 2-0 when Nikola Katic - in acres of space - nodded home at the far post.
And it was 3-0 on 62 minutes when the ball found its way in via Sadiq Umar and Latics defender Alex Bruce.
Wigan’s misery was compounded with 13 minutes to go when, after Jamie Walker was fouled in the area, Will Grigg’s penalty was saved by Rangers goalkeeper Wes Foderingham.
And Cook faces a major task - both on and off the pitch - to ready the players for Saturday’s big Championship opener against Sheffield Wednesday.
Latics started brightly enough, with Callum McManaman heading just wide from a corner and James Vaughan seeing a low shot well blocked.
At the other end, brilliant skills from Oviemuno Ejaria saw the Rangers man skip past three before being crowded out.
Ross McCrorie had Latics goalkeeper Christian Walton at full-stretch with a shot that flew inches past the far post.
But back came Latics and Nick Powell directed a header wide of the target before being adjudged to have fouled his marker while attempting another header, before a scramble that saw James Vaughan’s effort cleared off the line.
A late challenge from Sam Morsy then sparked a melee that saw Morelos run 50 yards to get involved in, resulting in both players getting booked.
Powell and Ejaria then got their legs in a tangle on the deck, with referee Bobby Madden requiring eyes in the back of his head to keep order.
The half-time whistle helped to calm things down, with Bruce reappearing for the second half in place of Burn.
Rangers flew out of the traps, and it needed a couple of great blocks by Chey Dunkley to keep the home side out, before Greg Docherty fired just over.
More good stuff from Rangers required Bruce to intervene, with Walton then doing well to tip another effort round the post.
The goal had been coming, though, and it duly arrived on 54 minutes.
This time Walton didn’t get to Daniel Candeias’ super cross, and Morelos headed in to an empty net.
Rangers took only four minutes to double their lead, when a corner to the far post was nodded home by Katic, this time Walton having no chance.
That was the cue for Latics to make wholesale changes...with Vaughan, Powell and McManaman being replaced by Grigg, Max Power and Walker.
But before the new men could get into the game, it was 3-0 Rangers as Umar headed into another empty net with Walton again unable to get to the cross.
Power might have done better with a header he directed straight at the goalie, before Leo Da Silva Lopes and Gary Roberts took over from James and Kal Naismith.
Latics had a great chance to pull one back 13 minutes from time when Walker was felled in the box for a penalty, only for Grigg to fluff his lines from 12 yards.
And Rangers could and should have applied salt to the wounds in the last 10 minutes, only for Jamie Murphy to blaze way over the top when clean through, before the Gers wasted a four-on-one break.