The Lightning is one of perhaps 10 teams “keeping fairly regular contact” with center Mats Sundin, the agent for the free agent center said.
   “Tampa has different people who have been talking to Mats on a regular basis,” agent J.P. Barry said Friday. “There is definitely sincere interest there.”
   Barry said Sundin, 37, who had 32 goals last season for the Maple Leafs, will begin serious skating next week and could be playing by mid to late December. Barry said he has yet to get a “short list” of potential teams from his client, but believes that could come by the end of November.
   There was no immediate comment from the Lightning.
  It would not be simple for Tampa Bay to make such a move. The team already has 14 forwards and it expects center Jeff Halpern (knee) to be ready by mid to late December. That means it would have to clear out roster and salary space.
   Sundin is expected to sign for about $7-million, pro-rated to the remainder of the season. If he signs on Dec. 12, that’s 60 days, one-third, into the season, so his contract would be for two-thirds of for whatever he signs.
   The Lightning salary cap number is about $52-million. The limit is $56.7-million.
   Finally, Sundin, who is good friends with Tampa Bay wing Gary Roberts, wants to play for a Stanley Cup. Where Tampa Bay stands in terms of playoff contention as things progress likely will have a big impact.