REPEAT the London Welsh third-quarter slump and Gloucester will run into trouble against Sale, warns Rob Cook.
Hailing the Cherry and Whites' progress in Europe and the LV=Cup, full-back Cook admits the Premiership is still the real deal.
And he believes the Kingsholm men must smarten up against Sale in order to register another league victory on Saturday (kick-off noon).
Gloucester eased past London Welsh 46-20 last Saturday with a six-try victory to get their LV=Cup campaign up and running.
Nigel Davies' men slipped off the pace after four first-half tries, before grabbing two more and sealing victory.
Cook expects a more rounded showing this weekend, to help Gloucester hit back to league action in style.
The 28-year-old explained: "There's still plenty of areas to work on, our second-half performance wasn't the greatest.
"If we play the way we did in the third quarter in a league match then I think we would be putting ourselves under pretty big pressure.
"We'd be in trouble if we did that against Sale I think.
"But we managed to hold out against Welsh and once again, that's to the credit of our resilience.
"I think we've used the last fortnight pretty well, though, and as long as we sharpen up a few areas we'll be ready for Sale.
"We dominated all areas in the first half against Welsh and it was frustrating to drop off in that fashion.
"But the win was important and Saturday was all about momentum for us."
Cook believes Gloucester will chase as much cup success as possible, even if the league breaks are good opportunities to blood youngsters and rest some frontline stars.
Gearing up for the league return, he continued: "These competitions are a great opportunity for a lot of players, and for us to work together in systems.
"But also – they are competitions that are there to be won – and we certainly want to make as much impression as possible.
"We were unlucky not to come away with more from the Ospreys and that was frustrating.
"But we're doing pretty well in all competitions at the moment, and we've got to keep that going now.
"These competitions are giving us chance to build and improve our systems and set-ups, and that allows us to build back towards the Premiership.
"Clearly that's the top focus, and we need to ensure we're in good shape when the league games come around.
"But at the same time we always go out to win, and it would obviously be great to be able to make good progress in those competitions too."