"I just think he's done a good job there most of the season. When those guys have bene together, they've been a really good line for us. They've been at their best. I thought Bert, in that spot yesterday, that he did a really good job for us and it's a good fit. Willy really likes playing with him."
As Keefe pointed out, it may very well be Nylander pushing to have Bertuzzi back on his line. Some players just feel more comfortable playing with certain teammates, and when he and Bertuzzi were playing together, we saw perhaps the best of Nylander. However, when Bertuzzi was removed from his line, we saw an uncharacteristic dip in his play, as Nylander went 4 straight games without registering a single point.
It remains to be seen if the reunion will work out, but the Maple Leafs are surely exhausting every option to find the best spot for Bertuzzi this season and the 2nd line might very well be it.