The Hoops added several players over the summer, with big things expected of Jozo Simunovic in particular.
Speaking to the Herald Scotland, McInnes said: “They’ve managed to sign some good players…If you spend £5.5m on a player [Simunovic] regardless of age, you would expect a level of ability.
“I think Ronny has signed some good players. They’ve managed to move on a few who weren’t making any impression and have managed to get a few in that will help them.
“Of course, they’ve lost van Dijk who for me was the best player in Scotland over the last couple of seasons.
“He was a big player for them but they’ve acted very swiftly to address that. We expect a tough match,” he added.
Whether or not Celtic’s transfer window can be deemed a success will surely be determined by how quickly new signing Jozo Simunovic can adapt to Scottish football.
The 21-year old comes extremely highly-rated from Croatia, but replacing the departed Dutchman will not be an easy task.
Van Dijk was a mainstay for the Hoops over the past two years and his composure and quality from the back was vital in Celtic’s style of play.
His ability to contribute in an attacking sense was also considerable and Simunovic will be doing very well if he is able to match the 10 goals achieved by the Southampton new boy last season.
The arrival of Manchester United academy graduates Saidy Janko and Tyler Blackett has also brought welcome depth to the Hoops’ backline and if all can hit the ground running, Virgil van Dijk could soon become a distant memory.