The Light Blues got their tour of North America off to a shocking start as they went down 3-1 in California as sloppy defending and a series of missed chances cost them dear.
Rangers are back in action on Saturday when they face Sacramento Republic before they head to Canada for another two fixtures.
A clash with English Championship side Derby will round off their summer schedule before the Gers host Hibernian in the first round of the Petrofac Training Cup.
McCoist said: "On [Tuesday night's] performance you would have to say we are a good bit away. We still have to train and prepare.
"We have got another three games here and we have got Derby as well. We are a good bit away. As disappointed as I am with the level of performance, I am not overly concerned that that is what we are going to get faced with week in week out.
"There is a lot of improvement there and that will certainly be the case."
After returning from their two-game tour of the Highlands and spending recent days putting his squad through their paces, McCoist had been hoping for a far better showing from his side in California.
The Gers boss tried out a 5-4-1 formation for the first time as Bilel Mohsni netted the only goal of the game for the visitors and the Ibrox boss was frustrated with a lacklustre performance.
"We have worked on a few things and trained the lads hard enough," he told RangersTV.
"But, at the same time, we left enough in their legs for them to play the game. It was disappointing.
"There was a slackness about us which I haven't seen in a long time.
"The boys were taking time on the ball, where normally they would have been firing it about to each other.
"There was definitely a slackness in our play that we will have to and certainly will eliminate."