Jack Capuano said Thomas Greiss delivered a “five-star” performance in Sunday’s 5-1 win over Toronto, but it didn’t make the Islanders goalie situation any clearer.

After starting just once in the Islanders’ first five games, Greiss was back in net Sunday for the third time in four games.

While Capuano declined to explain his decision-making process when going with Greiss over Jaroslav Halak, it’s become clear — thanks in part to Halak’s agent — that Halak isn’t pleased with the situation.

Halak, who started Thursday’s 4-2 loss in Pittsburgh, has seen his playing time decrease.

On Saturday, Halak’s agent, Allan Walsh, took to Twitter to express his displeasure with the Islanders’ decision to keep three goalies on the roster for the second straight season.

“Hard to figure out NY Islanders using [a three] goalie system for [second] year,” Walsh wrote. “Biggest issue is goalies don’t get enough practice time to stay sharp.”

Walsh continued: “Starting goalie for NY Islanders [in Thursday’s] game had only [one] quality practice in last [five] days before Penguins game. Going on [two] years of this now.”

SportsNet in Canada reported Islanders general manager Garth Snow is listening to offers for Halak. Snow declined comment.

The team doesn’t want to expose Jean-Francois Berube to waivers, fearing he could be claimed by another organization. But in the meantime, Berube hasn’t played this season.

“I like Allan,” Capuano said before the game. “He’s a good guy. I’ve had conversations with him and Garth — when I’m involved in those, but not too many. He’s got his opinion. I’m not gonna comment any more than that.”

Both goalies have been OK when they’ve been on the ice and Greiss said he was fine with the situations.

“We just do our work,” Greiss said. “I don’t think it’s tough. It’s out of our hands. I don’t worry about it. I make the best of it and play my game.”

Matt Martin, who made his return to Brooklyn on Sunday night after signing with Toronto in the offseason, received a standing ovation when a video tribute was shown during the first period.

Martin was one of three key departures from last year’s team, which also lost Kyle Okposo to Buffalo and Frans Nielsen to Detroit.

Martin, who signed a four-year, $10 million deal with the Maple Leafs after seven seasons with the Islanders, helped create a Toronto power play in the second and briefly scuffled with newcomer Andrew Ladd.

“I’m sure he’s glad that one’s over,’’ Cal Clutterbuck said. “I knew he was gonna throw around a little bit.”

“He’s meant a lot to us,” Toronto head coach Mike Babcock said. “It’s pretty nice not to have to worry. We don’t get our face washed much. Nobody takes advantage of us …”

Nikolay Kulemin returned after missing two games with an upper body injury and Alan Quine was a healthy.

Toronto’s Auston Matthews, the 2016 top overall pick, entered Sunday with six goals in his first eight games in the NHL. He was held without a point.