Jon Dahl Tomasson knew the trip to Rotherham would be a test for his young squad, but the Rovers boss can be pleased with the character they showed in the second half.

It was starting to look like another miserable afternoon at the New York Stadium was on the cards after Sam Szmodics missed from 12 yards and the hosts went in front thanks to goals from Hakeem Odoffin and Fred Onyedinma.

Onyedinma’s sending off was undoubtedly a turning point. The Luton loanee appeared to receive a second yellow card for encouraging referee Robert Madley to book a Rovers player.

But Rovers still had plenty to do at that stage, and Szmodics deserves huge credit for leading the comeback with a quickfire double. The attack-minded midfielder showed his inner steel to bounce back from a difficult first half, having also lost possession cheaply for the opener.

Tomasson made one change from the side that beat West Brom on the opening day, with Adam Wharton replacing Sondre Tronstad, who dropped to the bench.

It seemed to be a matter of time before the young midfielder returned to the starting line-up after a challenging pre-season, which was hampered by a combination of injury and illness.

Sam Gallagher returned to the squad after missing the first couple of games due to a knock picked up in training. The forward’s physical attributes seemed like a good fit against the Millers, who pose a major threat from set-pieces.

New signing Leo Wahlstedt was also named on the bench following his move from Norwegian club Odds BK. Tomasson explained ahead of the game that the Swedish international will not be rushed as he adjust to his new surroundings.

The opening stages were nervy, with both sides getting into some good areas but struggling to make a dent in the final third.

Rovers were handed a big chance to open the scoring after 15 minutes when Rankin-Costello was brought down in the box after reacting quickly to a loose ball.

Szmodics sent Viktor Johansson the wrong way from the spot but saw the ball bounce back off the foot of the post before Tyrhys Dolan volleyed wide on the rebound. It was inches away from being a perfect penalty but those are the fine margins in football.

The hosts went in front midway through the first half after a costly error by Szmodics, who seemed to be having one of those days. The midfielder’s loose pass fell to Odoffin and he made no mistake, smashing past the helpless Pears.

Rankin-Costello managed to get to the byline before picking out Hayden Carter in the box, but his shot was blocked by a defender as Rovers searched for an immediate response. Wharton also went for goal moments later but couldn’t keep his strike down.

Hyam made an important challenge on the stroke of half time as Hugill was about to pull the trigger after Rovers had again lost possession in their own half.

The second half got off to a frantic pace as Onyedinma was given too much space in the box and powered a header past Pears. The 26-year-old was booked before the restart, seemingly for his celebrations.

Just three minutes later, he had to leave the field. Matt Taylor, his assistant Wayne Carlisle and Johansson were all cautioned for their protests in a chaotic spell.

Tomasson’s substitutions had a big impact against West Brom and this trend continued, with the introduction of Niall Ennis, Ryan Hedges and Callum Brittain helping Rovers seize control following a triple change.

The squad might be stretched, but there is still a real hunger from the players coming off the bench to stake their claim for a starting place.

Brittain slotted into the backline, with Rankin-Costello taking up a more advanced position. The versatile full-back immediately found himself in the thick of the action, picking out Dolan in the box, but the youngster couldn’t keep his first-time effort down.

Some supporters have suggested the 24-year-old would be more effective higher up the pitch following his pre-season form, and he certainly gives Tomasson flexibility to tweak his system during games.

Gallagher also came off the bench 22 minutes from time – his first appearance since the goalless draw at Fleetwood in pre-season.

Rovers continued to have joy down the right flank and could have pulled one back when Hedges poked wide from close range after getting on the end of Brittain’s cross.

Rankin-Costello also sent a low drive from the edge of the area just wide of the post as Tomasson’s side kept applying pressure.

Goals were an issue at times last season, and it was starting to seem like Tomasson’s side would be left ruing their lack of potency in the final third.

But the breakthrough came when Szmodics found a pocket of space in the box. His shot brushed off a defender and wrong-footed Johansson.

The momentum had swung and it wasn’t long before Rovers got back on level terms in front of the travelling fans.

It was Szmodics again, latching onto Ennis’ pass and keeping his cool to go round the goalkeeper before slotting past a defender on the line.

The former Plymouth man has shown promising signs over the past few days, having also caught the eye against Walsall in midweek.

Ennis could be a major asset for Rovers over the coming season if he can stay fit, and Tomasson will be hoping his cautious approach with the forward will pay off in the coming weeks and months.

Harry Pickering went close in the final five minutes, but his dipping strike was kept out by a fine stop by Johansson above his head.

Hyam then thought he had scored the winner after turning home from Ennis’ cross-shot, but the defender was denied by the offside flag.

John Buckley also joined the action in stoppage time before Gallagher had a header saved by Johansson after rising well to meet Brittain’s cross. It looked like a moment written in the stars for a brief moment but the goalkeeper was equal to it.

Rovers now have seven days until their next league game against Hull after a busy start to the new campaign.

Tomasson’s side can take encouragement from their unbeaten start as they aim to build on last season’s seventh-place finish.

However, the new stoppage time rules will only increase the physical demands on the squad and the final weeks of the transfer window look set to be vital for Rovers’ hopes this season.