The 20-year-old's program was reduced last week after he discovered some soreness in his groin and hips.
While Clarkson conceded there was always concern when it came to groin complaints, he said the club was hopeful Rioli would be available for the Hawks' round-one clash with Melbourne on March 27.
"He was training the house down and performing really well with a lot of the stuff we wanted him to do," he said on Friday.
"We just needed to back him off and he's rested for a week and a half now so he'll rest for perhaps another week and then we'll get him going again.
"He's had a great pre-season and we want to make sure he's cherry ripe and ready to go for the start of the season."
The Hawks have taken a similar approach with Chance Bateman and Rhan Hooper, who are chances to play in the second NAB Cup game after being held back from Saturday night's clash with Richmond in Launceston.
Another to miss is recruit Shaun Burgoyne, who is set to join the main training squad next week after recovering from knee surgery.
He is expected to be available in either the last week of the NAB Cup competition or round one of the season proper.
Clarkson said the Hawks were optimistic about their chances in 2010 after putting together a longer pre-season than last year.
He also said it was pleasing to be in a position to field a strong NAB Cup outfit with Sam Mitchell, Lance Franklin, Luke Hodge, Brad Sewell and Jarryd Roughead all named to face the Tigers.
"We've selected the guys that are fit and have had really good preparations," he said.
"We're not resting any players. If they're fit and have had good preparation over the last four or five weeks, they're playing - which is most of our squad".
However, he said Saturday night's match was more about injecting match conditioning into the majority of his players than proving a point after a disappointing 2009.
"We want to make a statement in terms of having our guys fit but in terms of the win or the loss, we're not going to hang ourselves if we get beaten," he said.
"We like to win every game we go in to and it will be no different tomorrow night against Richmond."
Ruckman Max Bailey is also tracking well after his third knee reconstruction and has commenced running. He is expected to be available in the middle of the season.
