OTTAWA -- Erik Karlsson said Friday he has not considered signing a long-term contract with the San Jose Sharks, which he can do as soon as Jan. 1.

"Right now I'm worried about today," he said. "That's the mindset I've had all year. I'm trying to stay as focused as I can in the dressing room. The future is something I can't control."

The 28-year-old defenseman can become an unrestricted free agent July 1 after being traded from the Ottawa Senators on Sept 13. Ottawa offered Karlsson a contract extension, which he declined.

[RELATED: Karlsson at peace returning to Ottawa with Sharks]

Sharks general manager Doug Wilson said he envisioned a lengthy relationship with Karlsson when San Jose acquired him.

"It's a long-term approach and we think Erik fits for us for now, and for a long time," Wilson said at the time.

Video: Erik Karlsson returns with Sharks to face Ottawa

Karlsson, who has 15 points (two goals, 13 assists) in 26 games, struggled with San Jose to start the season, scoring his first goal in his 21st game. But he has settled in and has 11 points (two goals, nine assists) in his past 18 games.

His 47-point pace would be his lowest since 2010-11, his second NHL season, when he finished with 45 (13 goals, 32 assists). A two-time Norris Trophy winner as the NHL's best defenseman, Karlsson had 62 points (nine goals, 53 assists) in 71 games last season.

"It's different," said Karlsson, who will face the Senators for the first time since the trade at Canadian Tire Centre on Saturday (1 p.m. ET; TVAS, TSN5, NBCSCA, NHL.TV). "You try to fit in. You try to find your place. At the same time I've got to be who I am to help make us successful. I've been more comfortable the past month."

Coach Peter DeBoer has noticed.

"The past 15, 18 games, he's been excellent," DeBoer said. "The points are starting to come. His defense has been really good. Most nights he's been one of our better players, if not our best player.

"I think all that transition stuff is in the past, at least on the ice. Off the ice, I'm sure he's still getting used to it."

Karlsson said he and his wife, Melinda, have been enjoying life in San Jose after nine seasons with Ottawa, which selected him in the first round (No. 15) of the 2008 NHL Draft.

"It's been great," he said. "The Bay Area has been great. We've been out and about quite a bit. My wife loves it. It's been nothing but positive.

"Hockey-wise and life-wise, it's been a big adjustment. It's taken some time and [is] still taking some time but I've liked it. I've gotten as much enjoyment as I possibly can. There's nowhere to go but up."