Heineman scored a goal on four shots and added two hits in Monday's 7-5 win over the Sabres.
Heineman skated on the first line in Thursday's 6-3 loss to Washington. He logged one shot, one block and one hit over 11:29 TOI.
Heineman was called up from AHL Laval on Friday, according to Renaud Lavoie of TVA Sports.
Heineman was sent down to AHL Laval on Thursday.
Heineman was called up by Montreal on Wednesday.
Heineman was loaned to AHL Laval on Monday.
Heineman skated on the top line during the first day of training camp Thursday, Arpon Basu of The Athletic reports.
Heineman was assigned to AHL Laval on Monday.
Heineman (thumb) was activated from non-roster injured reserve and sent on loan to Leksands IF of the SHL, per CapFriendly.
Heineman will be sidelined for six weeks with a thumb injury.