Iron manager Russ Wilcox said his side make it difficult for themselves right from the start of Saturday's 2-1 home loss to Leyton Orient.
The hosts took the lead within two minutes through Scott Cuthbert, knocking Scunthorpe out of their stride after the positive home win over Coventry in midweek.However, United started the second period well and levelled with a well-taken goal from Matt Sparrow.
Nevertheless, within two minutes Orient were back ahead through a scrappy goal from Jobi McAnuff,
Wilcox said: "We shot ourselves in the foot. We spoke about getting on the front foot to build on Tuesday night.
"After two minutes, we're on to Plan B. We gave the ball away cheaply and found ourselves 1-0 down quickly.
"A lot was said at half-time, we managed to equalise quickly but we've conceded two cheap goals today.
"The goals against tally us not acceptable and is a massive concern. We need to score two or three to win a football match.
"We don't score scruffy goals but we concede them.
"We've been in the changing room a long time. Some harsh words have been said and we have to do so much better.
"You have to consider changes to the team because we've lost the football match. The game is still very raw and we'll assess things this week.
"We've been very hot and cold. I put out the same XI and rewarded the lads from Tuesday but we looked a different side at times."
Speaking about injuries, he added: "Lyle Taylor picked up an injury. Felt his abductor muscle go tight. It's the first time he's played two full games in a row for a while."
Wilcox also confirmed he will have a look at Nicky Featherstone and Rory Fallon in Tuesday's reserve home game with Mansfield, and that he is still looking to strengthen the squad with loan signings.
See much more from Russ Wilcox on The Iron Player.