Each week of the National Hockey League regular season, we will take a look at some of the most important injuries that have occurred in the last seven days, as well as key players that have returned from injury and updates on the conditions of other fantasy-relevant players (when applicable). Here is this week's batch:

1. Erik Karlsson, D, Senators (foot injury, day to day)

While it appears Ottawa has avoided disaster here, captain Karlsson will still miss the team's current three-game road trip through Western Canada. That said, Karlsson might be back next week. Therefore, hotshot rookie Thomas Chabot (who was recently recalled due to injuries to both Johnny Oduya and Ben Harpur), will probably not stick around upon Karlsson's return. Chabot is a risky fantasy option in non-keeper formats at this time.

2. Torey Krug, D, Bruins (returned from a broken jaw)

The Bruins' power-play quarterback returned to action much sooner than anticipated, as he decided to play with an extra protective piece of plastic around the jaw area. Krug wound up missing just one game. This is good news for Boston, but bad news for rookie rearguard Charlie McAvoy (who is now bumped from the top PP unit to the second team) and fellow freshman Matt Grzelcyk--who was sent down to the AHL after Krug's return.

3. Ryan Getzlaf, C, Ducks (returned from a lower-body injury)

The injury-ravaged Ducks were at least able to get back their captain and best player this week. Getzlaf was immediately inserted back onto Anaheim's top line alongside longtime partner Corey Perry. Joining them were both Ondrej Kase and Andrew Cogliano, who split time at left wing on Line 1. However, veteran winger Patrick Eaves could take over first-line duties next to Getzlaf and Perry once he recovers from his lower-body injury.

4. Nick Schmaltz, C/W, Blackhawks (upper-body injury, day to day)

This one could be either a big deal or a minor blip, depending on the severity of Schmaltz's upper-body injury. The Blackhawks' second-line center was injured in Game 1 vs. Pittsburgh but was able to start the following contest against Columbus (though he lasted only 34 seconds before aggravating his issue). Without Schmaltz to play with Patrick Kane and Ryan Hartman, Chicago is forced to utilize Artem Anisimov on the No. 2 unit. 

5. Patric Hornqvist, RW, Penguins (hand infection, IR, day to day)

The Stanley Cup hero missed Pittsburgh's first three games of the regular season but could be ready to return this week. That said, he may not get back his spot on the first power-play unit (which has gone to Jake Guentzel in Hornqvist's absence) and could start the regular season on Pittsburgh's third line. Both scenarios would dramatically reduce Hornqvist's fleeting fantasy value. Furthermore, he is in the final year of his contract.

6. Boone Jenner, LW/C, Blue Jackets (back injury, IR, day to day)

This injury sneaked up on hockey observers when the 23-man rosters were announced last week. However, back injuries are never a good thing. Jenner's absence has opened the door for rookie wingers Sonny Milano and Pierre-Luc Dubois to see more ice time. Once Jenner returns, one of the rookies may wind up on the fourth line (likely Dubois). For now, however, Jenner remains in a holding pattern. His fantasy value may take a hit. 

7. David Backes, RW/C, Bruins (illness, IR, out indefinitely)

The 33-year-old veteran has been diagnosed with diverticulitis and will likely miss at least the first month of the regular season. Backes's absence has greatly helped Frank Vatrano's situation, as the latter was almost cut from training camp after a so-so preseason. Vatrano was beaten out by rookie wingers Anders Bjork and Jake DeBrusk but has landed on his feet on the third line due to the Backes situation. Its now up to Vatrano to stick. 

8. Zach Parise, LW, Wild (back injury, day to day)

As mentioned above, back injuries can really be tricky to evaluate and handicap. Parise, however, seems to be doing a lot better and is back practicing with the Wild. There is a good chance he will return to action this week. The Minnesota player with the most to lose from Parise's return is Tyler Ennis, though Mikael Granlund's undisclosed injury may provide Ennis with a reprieve. Otherwise, look for Ennis to become the extra forward. 

9. Ian Cole, D, Penguins (mouth injury, out indefinitely)

One of Pittsburgh's steadiest citizens, Cole took a puck in the mouth against Nashville last week and will miss time. This should open the door for Chad Ruhwedel to play regularly for the next little while. A solid puck mover, Ruhwedel might be paired with Olli Maatta on the No. 2 defense unit (which could provide decent fantasy value, at least on a short-term basis). Cole's absence might also affect regular defense partner Justin Schultz.

10. Ryan Miller, G, Ducks (upper-body injury, IR, day to day)

The Ducks have the makings of a formidable duo in goal with John Gibson as the main starter and Miller as a quality, veteran backup. However, the latter remains on the sidelines due to an upper-body issue that seems to be lingering longer than expected. With Miller unable to play in the early going, Anaheim will turn to Gibson to play far more than originally planned. Third stringer Reto Berra might also see some action, but not much.