Gutierrez was left out for last weekend's defeat to Tottenham and revealed to a fellow Twitter user that his absence was not due to an injury.
On Thursday, Carver confirmed he had been involved in a disagreement with the Argentine, who had previously hinted at frustration on social media.
"There was a situation on the training ground, which happens. We have shaken hands like men," Carver said.
"We had a conversation and moved on like grown men."
Newcastle face Swansea City on Saturday looking to end a run of six straight defeats amid a backdrop of fan protests and fears of relegation to the Championship.
"We need a win. It's so important for everyone and may just lift that bit of gloom that's over the city at the moment," added Carver.
The Netherlands international was sidelined until January with a groin problem and then saw his initial attempt at a comeback thwarted by a collapsed lung - an issue he also suffered with while at Ajax in 2013.
However, Carver said: "Siem de Jong will be in the squad and be involved. Some of his play in the Under-21s at Aston Villa was excellent."
