VANCOUVER -- Defensemen Erik Karlsson and Johnny Oduya did not travel Monday with the Ottawa Senators for their three-game road trip through Western Canada.
The Senators begin the trip Tuesday against the Vancouver Canucks (10 p.m. ET; SNV, TSN5, RDS, NHL.TV), and coach Guy Boucher said it was too soon to rule them out for the rest of the trip. Ottawa plays the Calgary Flames on Friday and Edmonton Oilers on Saturday.
Karlsson, a two-time Norris Trophy winner as the NHL's top defenseman, missed the first two games recovering from foot surgery he had June 14.
Oduya sustained a lower-body injury in the season opener, a 5-4 shootout loss to the Washington Capitals last Thursday.
Karlsson and Oduya skated in Ottawa on Monday and could be back before the Senators play the Calgary Flames on Friday and the Edmonton Oilers on Saturday.
"They are both highly doubtful for [Tuesday] but you never know, might get a call and they are on a plane and they are here so I don't know," Boucher said. "They are skating and they are going hard so that's what I am waiting to see the results of."
Video: Erik Karlsson takes the No. 3 spot
Ottawa recalled defenseman Ben Harpur from Belleville of the American Hockey League to replace Oduya against the Detroit Red Wings on Saturday, but Harpur injured his shoulder during a 2-1 shootout loss and will be out at least one week.
The Senators recalled top defenseman prospect Thomas Chabot, 20, and defenseman Christian Jaros, 21, from Belleville on Sunday. Boucher is considering dressing seven defensemen and 11 forwards against the Canucks after finishing each of the first two games with five healthy defensemen.
"We need to find out what is going on back home, if we're getting a 'D' back, if we're not getting a 'D' back, if we're getting two 'D' back, that will have an impact on my decision," Boucher said.
Boucher said there's no way to replace Karlsson, who was runner-up for the Norris Trophy last season after scoring 71 points (17 goals and 54 assists) in 77 games and has led the Senators in scoring each of the past four seasons.
"If you take [Connor McDavid] out of Edmonton, if you take [Sidney Crosby] out (of Pittsburgh), those guys have such an impact, but Erik has even more than those guys because we are talking about sometimes 30 minutes a game and it's not just the forward attacking," Boucher said. "It's the breakouts, it's the transition starts with the 'D,' it's the O-zone straddling the blue line, it's the power play, it's the way you defend, it's the gap, it's everything and that's why a high-end defenseman like that impacts everything. It even impacts the goaltending because there is such a confidence factor there. We know it's gigantic hole for us."
Senators left wing Mike Hoffman, who was second on the Senators in scoring last season with 61 points (26 goals and 35 assists), missed practice Monday because of an illness, but might play Tuesday.