Ahcan signed a two-year, entry-level contract with the Bruins on Friday.
Rask may be considering retirement following the 2020-21 season, Matt Porter of the Boston Globe reports.
Bergeron has 31 goals, 56 points and a plus-23 rating in 61 games this season.
Marchand has 28 goals, 87 points, and a plus-25 rating through 70 games this season.
Pastrnak is currently tied with Alex Ovechkin for the league lead in goals with 48 in 70 games.
Grzelcyk scored a power-play goal on his only shot during a 2-0 victory over the Flyers on Tuesday.
Rask stopped 36 shots to post his fifth shutout in a 2-0 victory over the Flyers on Tuesday.
Halak will patrol the blue paint for Friday's road clash with Buffalo, Mike Loftus of The Patriot Ledger reports.
Rask will guard the net versus the Flyers on the road Tuesday, Mike Loftus of The Patriot Ledger reports.
Clifton (upper body) will return to the Bruins' lineup Tuesday night against the Flyers.
Krug (upper body) won't play Tuesday night against the Flyers, Joe Haggerty of NBC Sports Boston reports.
Carlo (upper body) will miss Tuesday's road clash with the Flyers, Amalie Benjamin of NHL.com reports.
Pastrnak scored a power-play goal in a 5-3 loss to Tampa Bay on Saturday.
Rask made 20 saves in a 5-3 loss to the Lightning on Saturday. He allowed four goals.
The Bruins activated Clifton (upper body) off injured reserve Saturday.
Kuhlman was assigned to AHL Providence on Saturday.
Rask will guard the home goal during Saturday's game against the Lightning, Kevin Paul Dupont of the Boston Globe reports.
Carlo (upper body) won't play Saturday against Tampa Bay, Amalie Benjamin of NHL.com reports.
Krug scored a goal and added an assist Thursday in a 2-1 overtime win over Florida.
Halak made 32 saves in a 2-1 overtime win over Florida on Thursday.
Carlo sustained an upper-body injury and won't return to Thursday's game against Florida.
Marchand (illness) scored a power-play goal on his only shot of the game in a 2-1 win over Tampa Bay on Tuesday.
DeBrusk scored the game-winning, power-play goal and had three shots Tuesday in a 2-1 victory over the Lightning.
Rask made 20 saves in Tuesday's 2-1 win over Tampa Bay.
Marchand (illness) took line rushes with the first unit and is expected to play Tuesday against the Lightning, Joe McDonald of The Athletic reports.