The Warriors grabbed a bonus-point in the 31-13 win over Connacht but they conceded 15 penalties in the process and saw Tommy Seymour and Chris Fusaro sin-binned in the second half.
“Our discipline was poor,” said Gregor in the Scotsman. “With the yellow card, one was a high tackle, which was disappointing. One I felt we had the numbers on the ball when Tommy Seymour got yellow carded.
“We’ve got to bring the penalty count down whether it’s through being offside three times or offside in defence, which isn’t good enough, and obviously with a few scrum penalties early on.
“So from today’s game we know we have to be better defensively. At times we were a bit passive. We’ve got to make sure our discipline’s better. So they’ll be the two main things from today.”
The Glasgow head coach confirmed second-half replacement Josh Strauss was withdrawn from the action as a precaution after an ankle knock.
“He just got a bang on his ankle and, look, it was to protect him,” said Gregor.
“He wanted to stay on but we’re in this stage of the season and obviously I think we’d got the bonus point already – it was an easy change to make.
“He’s taken a couple of knocks, more on his knee, over the last few weeks so I think it’s fine. He was desperate to stay on so he would have been okay to play but best to make sure he didn’t get injured.
“He was disappointed he didn’t get another try. He felt the offload was knocked on by one of the Connacht players but it was a great decision to draw the last man and put Adam (Ashe) in for a try.”
Gregor added: “Other than that, I think there’s the usual. Some guys hadn’t played for a while. Leone Nakarawa hadn’t played much rugby in the last five, six weeks, Ryan Grant, Euan Murray too, so I’m sure they’ll be feeling it in the morning but nothing major.”