TORONTO -- It's possible the long grind of the junior hockey season, including the Memorial Cup tournament that ended four days ago, will keep top 2013 NHL Draft prospects Seth Jones of the Portland Winterhawks and Nathan MacKinnon and Jonathan Drouin of the Halifax Mooseheads from participating in the fitness testing at the NHL Scouting Combine.

The trio is 1, 2, 3 in NHL Central Scouting's final ranking of North American skaters for this year's draft.

The agent for Jones and MacKinnon, Pat Brisson, told NHL.com his clients will undergo medical exams Friday as scheduled, but a decision on whether they would participate in the 13 individual tests designed to evaluate strength and fitness would be made afterward.

"In my opinion, you need about a week or two to get ready for some of those tests, and we have to respect what they've gone through here lately," Brisson said. "They're in game shape, but you have to treat them like Ferraris in a sense that now these athletes have to prepare for these things. Not that they can't do it, but we'll undergo the medical exam and take it from there."

MacKinnon, asked if he planned on participating in all the tests, told NHL.com, "I'm not sure. [Brisson] will make a decision [Friday]."

Jones also said he wasn't certain if he would take part in the full fitness testing program.

"Not sure yet," he said. "We'll see. I've been talking to my agent a little bit about that stuff. My body is definitely worn down. I played over 90 games this year in a short period of time with a lot of travel, a lot of time-zone changes."

Drouin told NHL.com he would he would do the fitness testing, but Allan Walsh, his agent, said that hadn't been decided.

"It's really tough when you've been through playoffs and the Memorial Cup … Jonathan's banged up with bumps and bruises and hasn't worked out at all since they won," Walsh told NHL.com. "He hasn't slept properly. He didn't get any sleep on Sunday when they won the tournament and then flew back to Halifax [from Saskatoon early Monday]. They had the parade [in Halifax on Tuesday] and then [Wednesday] he was on a plane at 4 a.m. to fly here. He then had two full days of interviews.

"[Wednesday] was his first full night of sleep since Saturday."

Drouin is scheduled to begin his medical and fitness test at 8:30 a.m., Jones at 9:30 a.m. and MacKinnon at 1:30 p.m.

The three top prospects and their agents spoke after a press conference announcing Jones, MacKinnon and Drouin had signed endorsement contracts with Reebok-CCM.

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