The AFL today met with former Blues assistant coach Tony Liberatore to discuss his claims that Carlton deliberately under-performed in some of their games late last season.
Asked if Carlton should be investigated, Matthews said: "Not from his (Liberatore's) comments".
But Matthews said losing was a "by product" of the AFL's draft structure.
"That's the system. You've got to take the bad with the good," he said. "The draft system is one of the planks of the competition. Most clubs over a decade or two have a chance of being a good team (because of it)."
However, Matthews believed introducing a lottery should be investigated.
"I think all those things should be looked at," he said.
"The draft has been such a good thing ... but issues pop up and the administrators have to weigh up the good and the bad."
Matthews said the definition of tanking had to be clarified, admitting there were some "grey areas" for coaches.
He called on the AFL to assure coaches they were not inadvertently breaking the rules by nursing players through the pre-season or booking surgery for their charges late in the year.
"There's a rule in there that says something like 'coaching on your merits'," he said.
"Clearly at times you are thinking of the medium-long term future ... rather than giving yourself the best chance of winning that week.
"That certainly happens in the pre-season. We say we are going to play 'Player A' for 60 minutes whether we are 10 goals in front or behind - that's obviously a higher priority than winning the game.
"And sometimes late in the year it's a higher priority to send someone for surgery - it doesn't help you that week but it helps you next season.
"There's a lot of grey areas, from the coaching point of view. The rule needs to be clarified a bit, particularly in the pre-season."
Matthews also described the recent AFL probe into Sydney coach Paul Roos as "ridiculous".
"Paul Roos was taken up because there was a sentence overheard that the AFL wanted to investigate ... it looked a bit ridiculous, the outcome was probably predictable," he said.
Meanwhile, Matthews called for an unlimited interchange after hardly being impressed by an NAB Cup trial.
During the official pre-season competition, teams were limited to 16 interchanges per quarter. "If you are going to have an interchange you might as well make it unlimited," he said.
"At some stage I thought 'don't have it at all, make it totally the survival of the fittest'.
"But if you are going to have it I'm not sure what it adds by limiting it."
