The man of the match in the 3-0 victory over Rotherham on Saturday scored a memorable strike as the Robins moved up to fourth place with seven games remaining.
And ahead of the clash with struggling Barnet, McGlashan says this campaign will be regarded as a failure if Mark Yates' men are not playing in the third tier next season.
"Anything less than promotion will be disappointing with the players we have here now," McGlashan told the Gloucestershire Echo.
"It's definitely the best squad I've played in because the gaffer has so many ingredients and he can change it when he needs to.
"We have real strength in depth and having players like Darren Carter on the bench shows that.
"We have seven cup finals to go and we know we can end up where we want to be."