Former Newport County and Cardiff City striker Matt Green fell out with manager Ian Holloway before Grimsby played the Exiles at Blundell Park.
Green, who started his senior playing career with County, and Swedish player Ludvig Öhman were both axed from the starting line-up by Holloway.
“Two of my lads ruined my plans because they were late arriving for the game,” said Holloway. “I was going to start Green instead of James Hanson, and Öhman instead of Mattie Pollock.
“But they arrived five minutes late. I would normally not have them in the squad, but two of my coaches, Ben Davies and Anthony Limbrick, said it was punishment enough not starting them, and that we might need them on the bench.”
Holloway’s pre-match decision paid off, though, with Grimsby winning 4-2, inflicting more damage on Newport hopes of closing in on the leading pack.
— Sky Bet League Two (@SkyBetLeagueTwo) February 26, 2020
Manager Michael Flynn’s Newport have taken only four points from a possible 18 in their last six SkyBet League Two fixtures and are now 16th.
County failed to score in four of those games and overall netted five goals and conceded eight during that run.
They have 13 matches left to repair the damage and their next test is against Oldham Athletic at Boundary Park on Saturday.
Jordan Green and Padraig Amond, with his 50th goal for Newport, scored for Newport, but Holloway’s team earned their sixth win in 12 matches since he took charge.
Home striker James Hanson was in danger of being sent off for an elbow on County Ryan Inniss during the first half – and the Grimsby man scored their third goal.
“He wasn’t sent off and I don’t know whether he should have been,” said Flynn. “All I do know is that Ryan has probably suffered a broken nose.
“The fact of the matter is we’ve conceded four goals and I’m not happy with that so I’m not making excuses.
“The defeat was disappointing. After the first 50 seconds we were a goal down and chasing the game.
📸 | It wasn’t to be for #NCAFC yesterday after a tough battle in Cleethorpes.
— Newport County AFC (@NewportCounty) February 26, 2020
“We did well to get back into it and should have taken the lead, but then their player [Josh Benson] hit a great free-kick and we were chasing the game again.
“We left ourselves a little bit open and they scored the third, we get back into it and then miss a couple more chances. The fourth goal came when we were all out trying to score the equaliser and left ourselves wide open.
“We created enough chances, especially. But if we’d scored four away from home, the bad thing about it is that we still wouldn’t have won the game. The goals we conceded weren’t good enough from our point of view.
“It’s frustrating because it’s uncharacteristic of us this season. Let’s hope it’s a one off.”
Bradley Garmston, after 50 seconds, Josh Benson (40 mins), James Hanson (61) and Max Wright (84)
Holloway said in his post-match press conference: “There were a few punches thrown either way weren’t there? You certainly got your money’s worth.
“I’d like it to go a lot smoother than that, but it never does.”
The match at Grimsby was rearranged from November because Newport had three players on international duty – goalkeeper Tom King, right-back Danny McNamara and Keanu Marsh-Brown.
It was the third time these teams have met this season, having clash twice in the FA Cup with Newport winning the replay 2-0 at Rodney Parade.
The return League Two match is in South Wales on Saturday, April 4.
Grimsby Town (4-3-3): James McKeown (capt); Elliott Hewitt, Luke Waterfall, Matthew Pollock, Bradley Garmston; Harry Clifton, Josh Benson, Elliott Whitehouse (Matt Green 59); James Tilley, James Hanson (Max Wright 66), Charles Vernam (Billy Clarke 77). Subs not used: Sam Russell, Ludvig Öhman, Elliot Grandin, Anthony Driscoll-Glennon.
Newport County AFC (3-4-2-1): Tom King; Ryan Inniss (Joss Labadie 46), Scot Bennett, Mickey Demetriou; Robbie Willmott, Dale Gorman, Josh Sheehan (capt), George Nurse; Jordan Green (Tristan Abrahams 71), Otis Khan; Jamille Matt (Padraig Amond 46). Subs not used: Ryan Haynes, Kyle Howkins, Matty Dolan, Lewis Collins.
Referee: Seb Stockbridge.
Attendance: 3,578 (33 Newport County)