The Blues’ plan might have been to play goaltender Jaroslav Halak on Sunday against Vancouver, but rookie Jake Allen might have changed those plans. Halak, who is battling back from a groin strain, was a full participant in the team’s Friday morning skate and could be ready to face the Canucks in the finale of the road trip. Halak missed his sixth consecutive game Friday. But four days after pulling out of a scheduled start because the injury was still nagging, the netminder feels like he’s close to a return. “This was the first full shot day for Halak,” Blues coach Ken Hitchcock said. “We’re hoping he can fully participate (Saturday), to get ready for Sunday.” But with Allen’s performance Friday against Calgary, playing the rookie on Sunday could give Halak an extra two days rest for his groin. Either way, the stable play of the rookie has benefited the Blues in two facets. “It bought us some time with Halak, and it’s allowed us to spend some time with Brian (Elliott), to hopefully get him back. It gave Brian a couple of days to look at video from when he played last year and how different it looks now. I think he’s got it back on track now.” Regarding the situation with Elliott, who did not play competitively during the lockout, Hitchcock said, “These are all good lessons for anybody, but this is another example of not playing and not having tutelage. Sometimes you get out of sorts a bit.”