Auston Matthews missing ahead of Game 4.

This is not a great sign if you're a fan of the Toronto Maple Leafs.

The Maple Leafs will look to take a commanding 3-1 series lead over the defending Stanley Cup champion Florida Panthers on Sunday night but things got off to a rocky start on Sunday morning when Maple Leafs captain Auston Matthews was notably absent. As the rest of his fellow Maple Leafs hit the ice for practice, including goaltender Joseph Woll who was once again in the starter's net, Matthews was nowhere to be seen.

Obviously the big concern here is whether or not Matthews will be available for Game 4, but no official update has come from the Maple Leafs as of yet.

Update: Maple Leafs confirm Matthews will play in Game 4.

It may very well be the case that Matthews is being given extra rest as he attempts to recover from some type of injury, as comments made by head coach Craig Berube on Saturday did cause me to raise a questioning eyebrow. Berube was discussing Matthews' lack of scoring in the playoffs with reporters and looked like he wanted to say more before cutting himself short and refusing to elaborate any further.

Of course nothing of the sort has been officially announced so that remains purely speculation on my part at this time.

Stay tuned for more on this rapidly developing story.