Callaghan had wanted his players to “put in a shift” and “give the fans something to shout about” on Friday. He changed the system to put more players up front, with three at the back.

“This left us a bit vulnerable at times. We were open to counter-attack and Bray tried to take advantage of that. But the lads did well and I certainly can’t fault them for effort.”

Callaghan was pleased with the performances of Bohs debutant Shane Fitzgerald and of lively winger Andy Mulligan, who made his first league appearance after an intensive campaign of college football.

But the schedule of two games a week is taking its toll on the squad. Callaghan will not have time to prepare fully for the challenge of an away Dublin derby and his selection choices are narrowing.

Several players have picked up injuries and will face late fitness tests. Derek Pender (calf) and Dave Scully (hamstring), who were crucial to Bohs’ efforts on Friday, are among the doubtful starters.

Stephen Paisley (knee), Conor O’Brien (ankle) have joined Owen Heary (knee) on the injury list.

The Bohemian manager expects St Patrick’s Athletic to improve this season on last year’s achievements. “They have a good squad, they’re on a good run and they have shown they can contend for the title,” he said of his former club.

Ex-Pat’s man Dave Mulcahy returned to Friday’s squad after illness and showed all the value of his experience when Bohs had their backs against the wall late in Friday’s game. His strength and guile will be required again on Monday, particularly in the possible absence of Heary, Paisley and Pender.

Eight of the last nine league games between Bohemians and Pats have been drawn or decided by a single goal either way.

“Maybe the players were a bit affected by having that game just three days after the trip to Limerick,” added Callaghan.

“The schedule is dictated to us without consultation and now we have another three-day break before the rescheduled match against Pats.”

In training Bohs have identified areas for improvement and talked through the recurring problems with individual errors.

“But we can’t blame players,” insisted Callaghan. “With a young squad you are more likely to have these errors and we have to keep supporting the young lads.”

The manager believes that Bohs fans understand that their team is a “work in progress – and in progress over two or three years” but the players and coaches “know the reality of where we are”.

“We haven’t given the fans a lot to shout about, especially at home. If we don’t put in a shift we can’t call on the fans as a twelfth man,” said Callaghan.

“I am a realist. We have to improve the results and if the system needs tweaking, that’s my responsibility.”

Friday’s game against equally youthful Bray assumes greater importance given Bohs’ recent record “but every game is a must-win”, insisted Callaghan, “whether we’re playing Bray or UCD or Shamrock Rovers”.

In the last ten league matches between the sides Bohemians have lost just once.

Having missed Dave Mulcahy last Friday, due to late withdrawal through illness, Bohemians may have to count without the experienced midfielder again. Dave Scully and Darragh Reynor (both illness) are also unlikely to be fit for selection, while Stephen Traynor is recovering from a medical procedure.

Captain Owen Heary (ankle) also remains sidelined, as he has been for over a month.

“The lads are working really hard in training and we’re trying to address those issues of concentration and communication,” he continued. If Bohs cannot get on a winning run “it won’t be for lack of effort”.

There were lots of positives in the team’s display on Tuesday, insisted Callaghan. Midfielder Shane Murray in his first league start was “brilliant” and he is “a fantastic prospect”.

Striker Kevin O’Leary was brought on late, and “we thought he might nick it for us”. He had scored a hat-trick in an earlier friendly against Irish Universities, and is showing promise and an eye for goal.

“I thought we dominated that game and were much the better side but sometimes the lie of the land just isn’t with you. It’s a cruel game. We were pegged back with another goal of the season contender [as with the first goal of the game against Derry City],” said Callaghan.

With Michael Barker and Shane Murray in for David Mulcahy and Stephen Paisley, the team’s average age dropped and youthful inexperience was a factor in the final outcome.

Callaghan and his coaching team, including a psychologist, will be giving more attention to the mental aspects of the game as they seek to eliminate the costly errors, but also to ensure the goal-scoring opportunities are taken.

“Seventy per cent of the game can be in your mind, and we have to address that,” said Callaghan. “One good thing about Tuesday’s game was that we probably had more chances than in any other this season. We changed the system a little to get more players forward, and I felt it worked.”

There may be some personnel changes for Friday as Chris Lyons (ankle) returns from a month-long lay-off, perhaps taking a place on the bench. Captain Owen Heary (knee injury) remains out.

“But we’ve got to go and we’ve got to play. We’ll just have to call on the full squad if necessary.”

Callaghan’s squad had a friendly against Irish Universities since their last league game. “It was a good competitive game and we won it very well, plus we got a full game for a lot of lads who haven’t played for a while.”

The squad have also worked hard on correcting what caused the home defeats by Sligo Rovers and Derry City. “We played well in those games for long periods, passing the ball well,” said Callaghan. “But it’s keeping the concentration that matters. A few key moments have cost us.”

The Bohemian manager notes that Limerick’s form has been similar to his own team’s, dropping points by narrow margins.

“They have been getting a lot of draws, and they came back with a late goal in their last match.

“They seem to be finding their way in this league but they’ve brought in some experienced players and they carry goal-scoring threats. We will need to be at our best to get a result.”

Bohemians will be without striker Chris Lyons (ankle) and captain Owen Heary (knee) on Tuesday, though Lyons may make it back for the following game.

“Their experience counted when Shelbourne had us pinned back for 20 minutes in the second half,” said Callaghan.

In his first league start for Bohemians Ciaran Nangle (pictured) did “really well, he brought a bit of balance to the team on the left side, and he showed calmness”, according to the manager.

Victory over Shelbourne moved Bohemians out of a group at the bottom of the table and“it was vital to get those three points”, Callaghan noted.

Derry will present formidable opposition, having scored seven goals in their last three games, while conceding none.

“They will be coming to us full of confidence. They have had a good start to the season. We have to make sure our preparation is right and we have to concentrate on our own performance, and make sure we don’t make those errors that cost us against Sligo”, said Callaghan.

Against Shelbourne, a couple of players who were starting regularly were rested, and one or two of those may come in again against Derry.

Michael Barker has joined the injury list with an ankle injury from training. Owen Heary (knee) and Chris Lyons (ankle) remain out.

Callaghan has sought to keep the whole squad tuned up with friendlies, like a short game played on Wednesday at the IT Blanchardstown complex. He has arranged another friendly against Irish Universities for the 11-day period between Friday’s game and the trip to Limerick on 16th April.