Guerin, 38, once was one of the NHL's top power forwards and was the Islanders' second-leading scorer with 16 goals and 20 assists in 61 games.
"I think it's worth a chance with a Billy Guerin, that playing with good players he will be able to score goals. I'm hoping he can re-energize his career here in Pittsburgh," Shero said. "I think it's a good move for both of us."
Guerin had been existing in a peculiar limbo since Friday, when he was pulled off the ice following warm-ups before the Islanders' game against the Buffalo Sabres. A deal reportedly was done with an Eastern Conference contender, and Guerin had waived his no-trade clause.
But nothing had happened by Monday, and he again was not in the lineup when the Islanders played the Colorado Avalanche that night.
As it turns out, the original deal fell through, Guerin said during an interview with TSN of Canada.
"It was a pretty painful process," Guerin said on TSN. "We thought we had a deal done with another team a couple of days ago. We were just waiting for something to happen. But this is a great opportunity for me, going to a talented team like that."
Shero can only hope this deal has an impact close to that of his last-second deal for forward Marian Hossa last year. That trade gave the Penguins the piece they needed to make a Stanley Cup run, and Hossa was a major contributor as they took the Detroit Red Wings to six games before losing in the finals.
Hossa later turned down a long, lucrative contract offer from Pittsburgh to sign a one-year deal with Detroit, and the Penguins have been searching ever since for a replacement talented enough to play alongside Crosby, who is third in the league in scoring.
Guerin, like Hossa last season, is in the final year of his contract -- he is making $4.5 million -- and is likely to remain with Pittsburgh only until the season ends.
The Islanders will receive a fifth-round pick if the Penguins do not make the playoffs. That becomes a fourth-round pick if the Penguins do get in. The Islanders will get a third-round pick if the Penguins win their first playoff round this year and Guerin plays at least 50 percent of the games.
By acquiring Guerin, the Penguins picked up a second top-six forward in less than a week. Chris Kunitz, acquired from Anaheim in a deal involving puck-moving defenseman Ryan Whitney on Thursday, has three goals in three games with Pittsburgh -- two in a 3-1 victory over Tampa Bay on Tuesday night.
Even without Crosby, who has a groin injury, the Penguins have won their past four to move into the top eight in the Eastern Conference playoff race after being ninth or lower for weeks. Crosby could return later this week.
It will be an unusual situation for Guerin, who is 38 and was the captain of the Islanders, because Crosby, age 21, is the current captain of the Penguins.
"I just go in and be myself. I've always been a vocal guy, not afraid to say anything. You just play it by ear. They get you for a specific reason," Guerin said on TSN. "The best thing you can do is be yourself and support the leadership they have there."
The Penguins also added some missing toughness, claiming right wing Craig Adams off waivers from the Chicago Blackhawks. Adams and Guerin are expected to be in uniform when the Penguins play the Florida Panthers on Thursday night.
Adams has two goals, four assists and 22 penalty minutes in 36 games with Chicago this season. He has 37 goals in 498 career NHL games with the Blackhawks and Carolina Hurricanes.
Forward Miroslav Satan, a disappointment this season, was demoted to Wilkes-Barre/Scranton of the AHL so that the remainder of his $3.5 million salary will not count against the Penguins' salary cap.
The 31-year-old Adams is in the final season of a $6 million, three-year contract and also can become a free agent after the season ends.
The Penguins also swapped minor league defensemen with St. Louis, sending Danny Richmond to the Blues for Andy Wozniewski, who was assigned to Wilkes-Barre/Scranton. Pittsburgh also reassigned forwards Bill Thomas, a Pittsburgh native, and Tim Wallace to Wilkes-Barre.
Thomas had two goals and an assist in 11 games during his latest stay with the Penguins.
Satan has three goals in eight games since the Penguins brought in Dan Bylsma as coach, but has only 17 goals and 19 assists in 65 games.
"It was for cap flexibility, basically," Shero said. "He's basically in a holding pattern right now and we'll see where we are the next couple of days."
The Penguins are 6-1-1 since Bylsma replaced Michel Therrien.
Information from The Associated Press was used in this report.