The youngster managed to grab a few hours sleep after arriving home around 2.30am before being pitched into today's Clydesdale Bank Premier League match against Gretna as an 83rd-minute substitute.
Rangers won the game 4-0 and a jubilant Naismith beamed afterwards: "To be honest, I didn't expect to play.
"I had quite a late night last night. I was told to come and meet the manager and the staff and I thought that would be all but it's great to get a run out.
"No words can describe how it felt. It has been ongoing for quite a while and I'm just glad it's all sorted. Hopefully now I can knuckle down and get on with my football.
"It was amazing to make my debut and I can't wait to carry that on now.
"I want to win trophies here. Every supporter, everyone at the club wants that and I'm no different.
"I'm not the finished article and hopefully I can learn from a lot of the boys in training and then maybe my time will come and I'll get a run of games."
Walter Smith was pleased to reach a favourable conclusion to a transfer saga which dominated the summer. Now he is expecting the SPFA Young Player of the Year to seize the opportunity to be a success.
"It was rather late on Friday night that we got him but we are delighted," said the Rangers boss.
"He has made no secret of the fact that he wanted to come to Rangers and we've been extremely keen to get him.
"We've got there now and we think we have a good player and one, we would hope after a settling in period, who would have a big impact for us."