The Draw for the EFL Trophy was made and the Mariners will face Premier League Champions Leicester City, Sheffield United and Walsall in Northern Group H.
The dates for the Group H fixtures have now been set.
The top two teams in each group will progress into the knockout stages of the competition, which will undergo a further review after the pilot is completed following the showpiece final at Wembley Stadium in April 2017.
Match Day 1 – w/c 29th August 2016
Sheffield United v Leicester City
Walsall v Grimsby Town
Match Day 2 – w/c 3rd October 2016
Grimsby Town v Leicester City
Sheffield United v Walsall
Match Day 3 – w/c 7th November 2016
Grimsby Town v Sheffield United
Leicester City v Walsall