The most important aspect though was giving game time to players who have been on the fringes and the likes of goalkeeper Matt Gilks, returning from a knee injury, and new signings Byron Webster, Kevin van Veen, Harrison McGahey and Adam Hammill.
The first half-chance came on 14 minutes when van Veen came to the near post but his effort was blocked and well dealt with by the visiting defence.
Two minutes later, a ball was played over the top to the Dutchman, who received the ball on the left side of the area. He took on his man but the Grimsby defender put in a good sliding tackle.
The 19th minute saw the first real shot of the game as a low bobbling effort from 25 yards by the visitors was well saved by Gilks.
United had their first real opportunity on 23 minutes, as Andy Dales and van Veen worked hard on the nearside touchline to win the ball back. Dales took the ball on, cut onto his right foot and saw his low effort from 25 yards curl just wide of the far post.
In the 26th minute, Grimsby went ahead as a cross from the left was met by the Mariners’ No 5, who headed into the net, despite the best efforts of Gilks.
Dales then showed a quick turn of pace to beat a player on halfway before cutting the ball around the corner for second year trainee Miracle Okafor, who was denied in the box by a good sliding challenge.
The game was played in three 30 minutes spells so that was the last opportunity before the first break.
Substitute Olufela Olomola had a chance right at the start of the second third, as youth trainee Jack Harrison floated the ball over the top for him. He chested the ball down, but sent the effort over the crossbar.
Gilks was then drawn into a good save on 35 minutes as the away side’s No 7 cut inside onto his right foot before shooting, with Gilks making a good save.
Clayton Lewis was next to come close on 36 minutes, as a corner was played short to Hammill. He then fed the ball to Lewis in the area and his powerful strike was beaten away for a further corner.
With 45 minutes on the clock, Olomola beat one man before sending a left-footed drive from 30 yards goalwards. The goalkeeper spilled the effort, but van Veen couldn’t quite get on the end of the rebound.
There was another opportunity six minutes later, as Olomola held up a cross into the box. The ball then dropped for Trialist B, who sent a half-volley over the top of the bar.
Olomola was soon fed by Hammill, but his low cross into the danger area was turned away as United searched for an equaliser going into the second break of the game.
There was a further raft of changes during that interval, as Gilks, van Veen and Hammill came off amongst others.
The first chance of this period fell to the Iron after great work from Olomola down the right, who drove from halfway and past two players. The cross was cleared to Tom Pugh, who saw his volley saved.
On 72 minutes, a corner was played to the head of Trialist B, but his effort went just wide.
Scunthorpe did level five minutes later though through Olomola. He was fed through on the left side of the area by Yasin Ben El-Mhanni before drilling the ball across the goal with his left foot.
Soon after, Kelsey made a fine stop down to his left as a Mariners player controlled the ball on the edge of the area before drilling an effort towards the corner.
Pugh had a powerful effort blocked in the 86th minute by a defender, as Lewis’ low cross was only partly cleared.
Then, Dales’ right-wing cross was knocked back across goal by Lewis for Okafor, but he slipped at the vital second as he looked for a shot on goal.
That proved to be the last chance of the afternoon, as the spoils were shared.
IRON: Gilks (Kelsey, 60), Webster, Trialist A (Dales, 60), Horsfield, Okafor (Harrison, 30, Ben El-Mhanni, 60), van Veen (Okafor, 60), Dales (Trialist B, 30), Lewis, McGahey, Pugh (Olomola, 30), Hammill (Pugh, 60).