After two wins in which the Bruins played so-so hockey, Claude Julien put his team through a hard 75-minute practice. Julien has not pleased with the play of his first and third lines, so he switched Milan Lucic and P.J. Axelsson to spark the units' play.

"I guess it's just preventing things from getting stale," said Julien. "Guys get comfortable in situations. Right now, those two lines have not been up to snuff in our regards. We just thought that maybe a little bit of a change there might give both lines a little bit of a spark."

While Lucic acknowledged not playing his best recently, Julien said the second-year winger wasn't the only player at fault, noting that his linemates have not been performing well either.

* Patrice Bergeron is still experiencing headaches. Bergeron suffered a concussion on Dec. 20.

* Andrew Ference has incorporated starts into his skating. Ference is rehabbing at Ristuccia Arena and is considered ahead of schedule. Ference has not tried hard stops while skating yet.

* Julien said he'll continue to experiment with his power-play units. Martin St. Pierre took several shifts with the No. 1 unit as the left-handed goal-line/net-front guy. Blake Wheeler replaced Lucic on the second unit.