We didn't disgrace ourselves - Johnson
Lee Johnson thought Derby County's Championship savvy proved decisive as Latics bowed out of the Capital One Cup following a 1-0 defeat.
Latics' manager took positives from the first-round exit, though he was disappointed by the way his side lost its way in the second half.
"Derby are a very good Championship side, but we didn’t disgrace ourselves. We played well and it was just disappointing how it fizzled out," explained Johnson.
He continued: "There are a lot of positive to take from the first half when we were on a par with them. We had chances and could have nicked a couple of goals.
"We took our foot off the gas in the second half when we powder puff and didn't have Derby's Championship savvy.
"We haven't anybody who has played regularly in the Championship and as a result we played into their hands.
"I found out that we are not quite Championship in our mentality, but in our play we can be when we are at our best.
"I thought over the 90 minutes they just edged us but, in fairness, we are a young side which is only going to get better."
Johnson was disappointed with the goal his side conceded as they were undone by a ball over the top of their defence.
Latics, who won 4-3 at Stevenage on Saturday in a thrilling opening league fixture, made one change to their starting line up as Jonson Clarke-Harris was preferred to Charlie MacDonald.
They made a lively start creating three clear-cut chances in the opening nine minutes as James Dayton, Cristian Montano and Jonson Clarke-Harris all went close.
Derby, who made six changes from their opening Sky Bet Championship match against Blackburn Rovers on Sunday, sounded a warning when Michael Jacobs headed against the crossbar before firing his side ahead in the 20th minute.
Conor Sammon raced on to a long ball over their defence and squared a pass from the left for Jacobs to fire high into the roof of the net.
Latics' keeper Mark Oxley pulled off a fine save to prevent Jeff Hedrick doubling Derby’s lead before they finished the opening period strongly as Dayton and Montano both had excellent chances, Montano forcing a fabulous save from keeper Lee Grant.
Grant was also extended by Clarke-Harris soon after the restart before the teenage striker limped off with an ankle injury to be replaced by James Wesolowski.
Ben Davies had a couple of decent chances for Derby who also had a couple of shouts for penalties waved aside while Johnson later conceded he thought they may be given.
Sidney Schmeltz and Kirk Millar were introduced midway through the half taking over from Dayton and Adam Rooney as Latics looked for an equaliser.
And it so nearly arrived in the 74th minute when Jose Baxter released Montano who was clean through on goal. He chipped Grant only for left-back Craig Forsyth to appear from nowhere to make a spectacular goalline clearance.
In the closing stages, which included six minutes of stoppage time, Latics went three at the back as central-defender James Tarkowski was pushed into attack as they went all out for an equaliser.
Sadly it never came, but Latics certainly made their Championship opponents battle every inch of the way for their victory.
Latics (4-4-1-1): Oxley, Brown, Tarkowski, Mellor, Grounds; Dayton (Schmeltz 66), Smith, Baxter, Montano; Rooney (Millar 66); Clarke-Harris (Wesolowski 56). Subs (not used): MacDonald, Byrne, Rodgers, Simpson.
Derby (4-4-2): Grant; Smith, Keogh, Buxton, Forsyth; Coutts, Hendrick, Eustace, Davies; Jacobs (Hughes 73), Sammon (Martin 75). Subs (not used): Bryson, Russell, Freeman, Bennett, Legzdins.
The goal: Jacobs (20) for Derby.
Bookings: Baxter (37), Grounds (61), Montano (86) for Latics. Martin (76), Hughes (90+5) for Derby.
Referee: Mr L Lewis.
Attendance: 5,000 (876 visitors).