Town boss Joe Royle felt his side were given a good test by Levski Sofia in their final pre-season game played in front of a disappointing 9,360 crowd at Portman Road.
It was the first time most Blues' fans had seen the new 4-3-3 formation in operation and Royle says this may not always be the way his side lines up: "We still have a lot of work to do, especially if we persist with the 4-3-3, although we will keep with the four at the back.
"I'm happy with the back four and when the front men are all playing well it is very dangerous, but when one gives the ball away then it is three men instead of two giving it away."
It is likely that Martijn Reuser or Jermaine Wright might be the midfield player coming into the side should Royle switch to 4-4-2, traditionally his preferred formation.
The Town boss was pleased with his new signings' performances: "Diallo was arguably the man of the match, Georges did his job well and Kelvin showed he is an excellent kicker of the ball even if he had nothing else to do all night."
Santos came off with a slight calf injury but it is not thought to be serious and he will be OK for next week. Chris Makin was left out of the line up as a precaution, the former Sunderland man has a thigh strain.