Andy Halliday fears Steven Gerrard's first season as Rangers boss will be branded a failure unless the Ibrox side lift a trophy.
Gers have made strides under the former Liverpool skipper this season, qualifying for the group stages of a European competition for the first time since 2010.
They remain in the Ladbrokes Premiership title hunt, although Celtic's midweek win over St Johnstone means Brendan Rodgers' Hoops have a six-point lead as they chase eight-in-a-row.
Having crashed out of the Betfred Cup to Aberdeen at the semi-final stage, the Light Blues' best chance of claiming silverware could come down to the William Hill Scottish Cup.
Gers held off League Two part-timers Cowdenbeath on Wednesday night to set up a fifth-round date with Kilmarnock, and Halliday admits defeat at Rugby Park on February 9 could wreck what is left of his team's campaign.
He said: "Our squad's had a lot of praise this year due to the progress that's been seen domestically and in Europe. We've managed to make it a real title race this year.
"But I still think it would be a disappointment and a failure if we don't win a trophy. It's as simple as that.
"This is a club that has a tradition based on winning things and if we were to walk away empty-handed again at the end of the season then we will be judged on that."
Halliday fired Gers ahead early on at Central Park as Gerrard's men threatened to blow Gary Bollan's Blue Brazil away.
But while further strikes from Kyle Lafferty and Lassana Coulibaly gave them a 3-0 lead at the interval, Rangers stepped off the gas after the break and almost hit the skids on a ground that doubles as a stock car track when they allowed Cowden's David Cox to pull one back.
They had to survive a few more scares and now Halliday has warned his team-mates they cannot afford a repeat of that sloppy second half against Steve Clarke's men after being given a demonstration of Killie's threat in last week's league defeat.
He said: "If I give it an honest reflection, I thought last night's game was won at half-time and that showed in the second-half performance. It was sub-standard.
"Credit to Cowdenbeath, they made it a lot more difficult for us while the pitch was starting to freeze up too.
"But there are no excuses. The second half was lacklustre.
"That is a habit we don't want to continue. We've played Kilmarnock twice at Rugby Park this year. I thought we gave one of our best performances of the season there in August – then one of our worst last week.
"We need to be that better version of ourselves if we're going to go through to the next round."
Lafferty grabbed his first goal since September and Halliday was delighted to see the Northern Irishman end his scoring drought.
"Strikers are there to score goals and there has been a lot of games this season where Kyle has come on, made an impact, done well but maybe not been rewarded for that," he said. "So I was very happy that he managed to get his goal last night.
"I don't score too many these days but it was nice to grab one myself. I don't think the Cowdenbeath lad who closed me down knows too much about me as he thought I was going to shoot on my right foot.
"I was able to chop back onto my left and I caught it well. I was delighted to get the goal."
