Kevin Ellison joined his joint-top scorer Jack Redshaw and midfielder Ryan Williams in committing to the Shrimps when he put pen to paper on a renewed deal ahead of the 3-0 win over Rochdale.
Roche, whose own deal runs until the end of next season, told Press Association Sport: "It's very encouraging.
"We're in a position this season where we've got quite a lot of players out of contract and, if you look at other clubs around the league, a lot of clubs have said they're not looking to sign up players until the end of the season.
"So the fact that we've got three of our big players on board early doors is a real bonus for next season."
Ellison celebrated his contract extension with a spectacular 35-year volley against Dale - a strike that left Roche astonished.
He added: "It's the best goal I've ever seen live. As he was about to hit it, in my head I was thinking 'what are you doing? There's no way you'll score from there'.
"But as soon as it left his foot there was only one place it was going and that was the top corner rather than over the stand."