The Leeds boss's decisions have been called into question.
Leeds had been on course for their fifth straight win at Elland Road after Chris Wood struck midway through the first half.
However, the Whites failed to kill off their opponents, who rescued a point in second half stoppage time through Shaun MacDonald - a teammate of Leeds boss Monk at Swansea City.
Afterwards, Monk's decision to substitute key trio Pablo Hernandez, Hadi Sacko and Wood was criticised by many, with the hosts appearing to suffer a lack of momentum thereon in.
Bartley though, believes that with three games in eight days, Leeds' changes were necessary.
Asked if he would agree with the above assessment, the on loan defender told the BBC: "It's difficult you know. The fans, media they don't always know the whole picture.
"Woody's been away with internationals and Hadi's been struggling a lot with a couple of knocks. It's a long season and the players need protection.
"Obviously the gaffer's made what he thought was the right decision, but then it's on to the players who come in in their place for them to bring us something else and to have an impact on the game. And it's up to us who are already on the pitch to make sure we continue that momentum and we don't let it slip.
"We've all let ourselves down a little bit. There's no one to blame. It's about us taking more responsibility and making sure we kill the game off."
Leeds would have gone ninth and a point off the play-offs had they held on against Wigan, but remain in 13th position.
Monk's men, who lost 1-0 against Derby County in their previous outing, travel to 15th-place Wolverhampton Wanderers on Saturday afternoon.