Sidney Crosby was back on the ice Thursday, but his status for the remainder of the playoffs remains unclear. (AP Photo/Nick Wass)

PITTSBURGH — Sidney Crosby skated at the Penguins’ practice facility Thursday morning, but there is still no timetable for his return from a concussion sustained Monday. Penguins Coach Mike Sullivan said Crosby is still “in the process” and is day-to-day as of now.

“I’m not going to elaborate on the process he is going through, we really elaborate on our medical staff in that regard,” Sullivan said. “These guys advise us and they’re very good at what they do. So he is in the process right now, and will continue to be, and it will continue to be a day-to-day evaluation and we’ll go from there.”

Crosby was on the ice Thursday just three days after he sustained the concussion on a hit by Matt Niskanen in the first period of Game 3, but that was not necessarily an indication he will be ready for Game 5 in Washington on Saturday. 

The Penguins scratched out a 3-2 win in Crosby’s absence Wednesday night, and now lead 3-1 in the series. The Penguins were already playing without top defenseman Kris Letang, No. 1 goaltender Matt Murray, and Conor Sheary, who also missed Game 4 with a concussion.

And while those other holes have been readily patched — the Penguins’ defense has been sharp in the playoffs and goaltender Marc-Andre Fleury has been even sharper — Crosby’s status remains a key for the Penguins in this series, and potentially beyond it. The Hart Trophy finalist led the NHL with 44 goals this season, and had two goals and two assists in this series in Games 1 and 2 against the Capitals. 

Since he left the ice after Niskanen’s hit, the Penguins have two five-on-five goals, two six-on-five goals and a power-play goal in close to 120 minutes. The two five-on-five goals came on an unlikely breakaway for Patric Hornqvist and when Jake Guentzel banked the puck off Dmitry Orlov’s skate and past an out-of-position Braden Holtby. The power-play goal was scored on a point shot by Justin Schultz, and was just the second tally in the Penguins’ last 13 five-on-four advantages. Excelling on the power play does not get any easier with Crosby on the shelf.

“I think we all know each person has to step up when you lose a guy like that,” Guentzel, who had been on a line with Crosby in the playoffs, said Tuesday. “It takes everyone.”

Sullivan built his Game 4 lines around a core of Evgeni Malkin and Phil Kessel, and they continued using their speed to get behind the Capitals’ net and blitz the crease with abandon. At the start of the contest, Malkin and Kessel were on the top line with Chris Kunitz. Guentzel, Nick Bonino and Bryan Rust formed the second line, while the third was comprised of Carl Hagelin, Matt Cullen and Hornqvist, Scott Wilson, Carter Rowney and Tom Kuhnhackl skated together as the fourth trio.

But those lines were shuffled a bit throughout the game, and there is no reason to think Sullivan won’t shuffle them again ahead of Game 5. The Penguins finished with the NHL’s second-best record despite 282 man-games lost to injury during the regular season. That included stints without Crosby and others without Malkin, and Sullivan is familiar with effectively patching holes.

“Well like we always do, we tried to put line combinations together that we think will help us execute the game plan and have success,” Sullivan said Thursday. “So that was the question we asked ourselves when we put together the combinations that we did. We made some in-game adjustments to our line combinations, based on how the game was being played and what we saw, and we went from there.”

It is clear, and understandable, that the Penguins’ offense has lost some rhythm without its star captain on the ice. But Crosby’s concussion history clouds his potential return date.

In the 2011 Winter Classic, then-Capitals center David Steckel delivered a blindside hit to Crosby’s head. Four days later, Crosby was driven into the boards by Tampa Bay Lightning defenseman Victor Hedman. Crosby ended up missing 48 games in the 2010-11 season, 20 games at the start of the 2011-12 season and, after returning for eight games, missed 40 more that season with concussion-related symptoms.

Then Crosby was concussed during training camp prior to this season and missed the first six contests as a result. Crosby frequently skated while working back from his previous three concussions, and those instances came at various points of his recovery processes and didn’t always indicate he was nearing a return. This current concussion is the fourth reported one of his career. Wednesday made it 115 career games missed due to head injuries, and that number could grow Saturday.

“I think over the years you’ve been on teams when your best guys are out,” Penguins forward Scott Wilson said prior to Game 3. “So it’s kind of second nature to just kind of adapt to that.”