The Shrimps announced Will Haining's departure after Saturday's season-closing victory at Southend, the player following fellow defender Nick Fenton out of the door after financial constraints prevented contracts being offered to the duo.
The deal of Roche, 31, means he is already on board for next term and the Irishman believes boss Jim Bentley and assistant Ken McKenna will ensure the squad is well stocked for 2013/14.
"It's not really a concern because the players are always the last to know," he said. "We don't know how many cuts (there will be) and what exactly is going to happen.
"We'll find out a lot more over the coming weeks but the gaffer and the assistant manager are very hard-working.
"They go to see games every week so they'll have plans in place.
"If they have to let players go there's no doubt about it that they'll have replacements lined up."
Reflecting on the recently completed campaign, Roche was satisfied with his own form despite a couple of hiccups in the heavy defeats to Fleetwood and Barnet.
"Honestly, I've been pretty pleased," he added. "I think I had a bit of a patchy start to the season, ending up in the Fleetwood game - the less said about that game, the better from my point of view.
"But since then I've been really pleased. I had a crazy 20 minutes spell at Barnet, giving a couple of goals away and getting sent off which obviously wasn't my finest hour, but overall since the Fleetwood game I've been really pleased."