On the opening day of NHL free agency on Friday, the Rangers went for low-cost speed and upgrades in their penalty-killing units, signing forwards Michael Grabner, who played five seasons with the Islanders, and Nathan Gerbe, a small but feisty winger who has played for the Sabres and Hurricanes.

A trade — perhaps with a Western Conference club such as Colorado or Anaheim — remains a possibility, but with limited money available, the Rangers were not expected to toss big dollars at the top free agents.

Grabner, 28, who received a two-year deal averaging $1.6 million per season, appears to be the replacement for fourth-liner Dominic Moore, an unrestricted free agent. Gerbe, who will be 29 later this month, received a one-year contract worth $600,000. Both should improve the Rangers’ 26th- ranked penalty kill (78.2 percent), which skidded from the No. 6 spot (84.3 percent) in 2014-15.

They also added depth defenseman Adam Clendening, 23, who has played for several teams, on a one-year, two-way deal worth $600,000 at the NHL level and $300,000 in the AHL.

A native of Austria, Grabner has proved his worth on special teams in his seven seasons with the Islanders, Canucks and Maple Leafs. He is tied for fourth in the NHL in shorthanded goals (12) since the start of the 2010-11 season and last season ranked second among NHL forwards in shorthanded ice time at 248:29. Overall, he has 173 points in 397 games.

“Excited to be back in New York once again . . . this time on the other side of the battle,” Grabner said on his Twitter account.

Gerbe had 59 points in his last three seasons in Carolina and likely will be a fourth-liner as well.

Clendening, who was drafted out of Boston College in 2011, has played with five NHL teams. He skated in 29 NHL games with Pittsburgh and Edmonton this past season, recording a goal and six assists, a plus-six rating and 20 penalty minutes.

The Blueshirts also agreed to terms with defenseman Michael Paliotta, 23, a native of Westport, Connecticut, who played for the Lake Erie Monsters.

The Rangers aren’t finished. General manager Jeff Gorton continues to listen to trade offers, and Brandon Pirri, Jiri Hudler, P.A. Parenteau and Teddy Purcell are among the remaining available free-agent forwards.

Beukeboom on staff

The Rangers filled in a missing piece on their coaching staff, adding former Stanley Cup-winning defenseman and minor-league coach Jeff Beukeboom to replace assistant Ulf Samuelsson, who left two months ago to coach the AHL’s Charlotte Checkers. Beukeboom, 51, who won three Cups with Edmonton and one with the Rangers, has helped develop Rangers defense prospects Dylan McIlrath, Brady Skjei and Ryan Graves with the Hartford Wolf Pack, where he has been an assistant for four years.