The initial wave of NHL free-agent signings is over, but there is still plenty of time and opportunities for teams to improve their rosters.

Trades are the likeliest way to make that happen, although there are also some high-profile restricted free agents who could be poached with big offer sheets.

Here is a closer look at some of the biggest names who may be available, as well as a rundown of the teams that may make a play for their services before the offseason is over.

Mitchell Marner

Offer sheets are rare in the NHL, but with the Carolina Hurricanes having already matched the Montreal Canadiens' pitch for forward Sebastian Aho's services this offseason, Toronto Maple Leafs forward Mitchell Marner could be next to receive one.

According to David Pagnotta of The Fourth Period, the Canadiens and New York Islanders might be interested in signing Marner to offer sheets.

Pagnotta noted that while the Isles are "serious" in their pursuit of Marner, the Habs may prefer to go after another restricted free agent in Winnipeg Jets winger Patrik Laine.

Although there are undoubtedly teams interested in a player of Marner's ilk, Pagnotta added that Marner and the Leafs have been in contract talks, which means an offer sheet is far from guaranteed.

The 22-year-old is coming off a career year in which he registered 26 goals and 68 assists for a team-high 94 points. It was a big leap for the 2015 No. 4 overall pick, who had 61 and 69 points in his first two seasons, respectively.

Marner was aided significantly by the signing of John Tavares, who played alongside Marner for much of the season and finished with a team-high 47 goals thanks to Marner's passing ability.

Despite their immense talent, the Leafs have failed to get out of the first round of the playoffs in each of the past three seasons, and they haven't won a playoff round since 2004.

If either the Islanders or Canadiens sign Marner to an offer sheet, it would come with some intriguing subtext. The Maple Leafs signed Tavares away from the Isles last offseason, and the Habs are perhaps Toronto's greatest rival.

Toronto can ill afford to let either of those teams acquire one of their best players, and it is difficult to envision the Leafs allowing Marner go anywhere because of the risk of a drop-off they simply can't afford.

Nikita Gusev

Forward Nikita Gusev's future is uncertain as a restricted free agent for a Vegas Golden Knights team that has no cap space.

Vegas has worked furiously to get under the cap by trading the likes of forward Erik Haula and defenseman Colin Miller, but if it can't create more space to sign Gusev, it may have no choice but to trade him.

Jim Matheson of the Edmonton Journal suggested that as many as 10 teams could be interested in trading for Gusev, and he singled out the Colorado Avalanche.

The Avs have a ton of cap space, and Matheson noted that they have the ammunition to get a deal done, including their 2020 first-round draft pick.

Colorado needs some secondary scoring to support the top line of Nathan MacKinnon, Mikko Rantanen and Gabriel Landeskog, and Gusev may be a perfect fit. Although he has never played an NHL game, the 27-year-old winger has a history of success in the KHL.

During the 2018-19 season, Gusev registered 17 goals and 65 assists for a league-high 82 points in 62 games with SKA Saint Petersburg. He also added 19 points in 18 playoff games.

The Knights signed Gusev to a one-year deal in April, and the possibility existed for him to suit up for the team during the playoffs, but that never came to fruition. Gusev is technically under team control, but Vegas may not have the means to keep him.

Since the Golden Knights already have a stacked forward group that includes Mark Stone, Max Pacioretty, William Karlsson, Jonathan Marchessault, Paul Stastny and Reilly Smith, they can afford to lose Gusev, but they may have to watch him blossom and thrive on a rival team like Colorado, which would be a tough pill to swallow.

Jesse Puljujarvi

Of all the NHL's young players, perhaps nobody would benefit from a change of scenery more than Edmonton Oilers winger Jesse Puljujarvi.

When the Oilers took Puljujarvi with the No. 4 overall pick in the 2016 draft, it was expected that he would fit in seamlessly with the likes of Connor McDavid, Leon Draisaitl and Ryan Nugent-Hopkins, but the Finn has yet to gain his footing.

As a result, the restricted free agent has been the subject of trade speculation this offseason.

According to Dennis Bernstein of The Fourth Period, the Los Angeles Kings checked in on the possibility of acquiring Puljujarvi, but they balked when asked to take on veteran winger Milan Lucic's contract as part of the deal.

Lucic makes $6 million per year through 2022-23, per CapFriendly, and landing Puljujarvi wouldn't be nearly enough incentive to entice the Kings or any other team to take that albatross of a deal. The 31-year-old has scored a combined 54 points in the past two seasons.

Puljujarvi is a big, skilled player, but he has just 37 points in 139 career NHL games. Last season, he had just four goals and five assists in 46 games.

He career highs came in 2017-18, when he recorded 12 goals and eight assists in 65 contests.

Puljujarvi doesn't appear to be a fit in Edmonton any longer, and unless he gets extended playing time alongside McDavid or Draisaitl, it is difficult to envision him succeeding with the Oilers.

If another young team can find a spot for Puljujarvi in its top six and land him without having to take on Lucic, he could be a worthwhile flier given the potential he seems to possess.