Grimsby returned to action following a period of self-isolation to collect a first point of the season with a goalless Sky Bet League Two draw at misfiring Bolton.
Ian Holloway's Mariners had not played since September 19 and only resumed training on Friday after Jock Curran's positive coronavirus test.
Despite the three-game lay-off, Grimsby produced a spirited performance against opponents who are still to win at home under manager Ian Evatt.
Bolton, looking to build on their first victory of the campaign against Harrogate, had the better of the first half without testing goalkeeper James McKeown.
Ali Crawford fizzed two free-kick kicks wide of the target and a third effort was blocked by Luke Waterfall.
Instead of capitalising on their possession after half time, Bolton failed to create any worthwhile chances.
And it was the visitors who threatened to beat the Trotters for the first time since 1982, with substitutes Montel Gibson, Owura Edwards and Terry Taylor all working openings for shots without troubling keeper Billy Crellin.