RICHMOND young gun Sydney Stack's contract celebration has been soured with the 19-year-old appearing to suffer a calf injury at training.
Stack left the training ground early on Thursday, less than an hour after the Tigers announced he had signed a new deal taking him through to the end of 2021.
The extent of his injury is unknown but he would appear to be in doubt for Saturday night's clash with Melbourne at the MCG.
Coach Damien Hardwick had earlier lauded Stack, who had been overlooked in the NAB AFL Draft by every other club after having off-field issues in his native Western Australia.
"If you had have said to me at the start of the year that we would have drafted this kid as the last pick in the draft and he'd play every single game and be a Rising Star candidate, I'd look at you as if you were crazy," Hardwick said.
"But he's been nothing short of outstanding. He's only going to, I feel, get better and better as his fitness progresses.
"If he continues to work hard and continues to decide this is what he wants to be, the world's his oyster."
With the Tigers having surged into the top four with five wins in a row, premiership ruckman Toby Nankervis will wait another week for his AFL return.
Nankervis will instead play in the VFL for a third-straight week as he continues his comeback from a groin injury that kept him sidelined for two months.
"The significance of his injury with the position he plays ... with the ability of him to be competitive in the ruck contests, we just feel it would be a really good decision for us to give him an extra week," Hardwick said.
"Trying to tell 'Nank' that was pretty tough, as you can imagine. He's a very competitive man and wants to play.
"But he understands where we are at the moment and he also understands how important he is to the make-up of our side."
Hardwick said the form of incumbent rucks Ivan Soldo and Mabior Chol would make for a difficult selection call when Nankervis was ready to return.
"Whether we go by a 'ruck by committee' approach going forward for the remainder of the year is yet to be seen - Soldo versus the talls, Nank versus possibly the smaller-type ruckman," Hardwick said.
"That's something that we've now got up our sleeve that we're really excited about." - Damien Hardwick
Hardwick insisted the Tigers would not necessarily put Trent Cotchin (hamstring) on ice until the finals, although the skipper will miss at least the next two games.