NEW YORK -- The NHL and NHL Players' Association went a second straight day without a formal in-person negotiating session, although the sides remain engaged in mediation.

The league and union met separately with federal mediator Scot Beckenbaugh during a series of meetings that spanned the whole day Friday and late into the evening. They will continue that process Saturday morning.

It isn't yet known if the league and union will meet face-to-face Saturday, the 112th day of the lockout. The sides have less than a week to reach a new collective bargaining agreement to save what would likely be a 48-game hockey season.

Few details emerged about the scope or subject matter of those meetings and whether progress was forged, although a source told ESPN that both sides expressed signs of flexibility to the mediator.

With exactly one week left until the league's self-imposed deadline of Jan. 11 to reach a deal, the NHL and NHLPA have resorted to "shuttle mediation" since the fallout from the last time they met in person Wednesday night.

That negotiating session was marked by the NHLPA's decision not to file a disclaimer of interest by the midnight deadline, although the hope that a new deal could be close abated Thursday morning after reports of tension between the sides.

The NHLPA was angered by the league's attempt to change language in one area of the CBA, that which pertains to the penalization of teams that are found guilty of hiding hockey-related revenue.

That issue has since been resolved, a source informed ESPNNewYork.com, although the lack of trust between the sides seemed to resurface.

The NHLPA initiated a vote Thursday evening to provide again the union's executive board with the authority to file a disclaimer of interest. The 48-hour voting window expires Saturday at 6 p.m. ET.

With no formal negotiations between the sides since midweek, nerves continue to fray with the season hanging in the balance.

All regular-season games already have been canceled through Jan. 14, and NHL commissioner Gary Bettman has set Jan. 11 as the deadline to reach a new CBA and avoid the entire season being scrapped.

The sides have traded four proposals in the past week -- two by each side -- but none has gained enough traction. Getting an agreement on a pension plan likely would go a long way toward an agreement that would put hockey back on the ice.

NHLPA executive director Donald Fehr believed a plan for players-funded pension was established before talks blew up in early December. That apparently wasn't the case, or the NHL has changed its offer regarding the pension in exchange for agreeing to other things the union wanted.

The salary-cap number for the second year of the deal -- the 2013-14 season -- hasn't been agreed to, and it is another major point of contention. The league is pushing for a $60 million cap, while the union wants it to be $65 million with a floor of $44 million.

In return for the higher cap number players would be willing to forgo a cap on escrow.

Both sides seem content on the deal lasting for 10 years, but they have different opinions on whether an opt-out should be allowed to be exercised after seven years or eight.

The NHL proposed last Thursday that pension contributions come out of the players' share of revenues, and $50 million of the league's make-whole payment of $300 million will be allocated and set aside to fund potential underfunded liabilities of the plan at the end of the collective bargaining agreement.

Last month, the NHL agreed to raise its make-whole offer of deferred payments from $211 million to $300 million as part of a proposed package that required the union to agree on three nonnegotiable points. Instead, the union accepted the raise in funds, but then made counterproposals on the issues the league stated had no wiggle room.

"As you might expect, the differences between us relate to the core economic issues which don't involve the share," Fehr said of hockey-related revenue, which likely will be split 50-50.

The NHL is the only North American professional sports league to cancel a season because of a labor dispute, losing the 2004-05 campaign to a lockout. A 48-game season was played in 1995 after a lockout stretched into January.

Information from ESPN.com's Pierre LeBrun and The Associated Press was used in this report.