Widnes slipped to eighth in the table after a 30-16 defeat to Halifax at The Shay last Thursday night.
“I think people can look at reasons like the injuries and the coaching situation, but there can be no more excuses,” Pickersgill told the Runcorn and Widnes Weekly News.
“There’s definitely a massive sense of under-achievement from the lads, so we need to do better than we have done.
“After defeat in the Northern Rail Cup against Batley, our focus is purely on the league now. But if we don’t get a win at the weekend then it is going to be difficult to reach the play-offs, so it’s a massive game for us.”
The Vikings suffered a 42-38 defeat at the hands of Toulouse at the Stobart Stadium Halton earlier in the season, and the French side join Widnes, Batley and Sheffield in the race for the play-offs.
Widnes would have sat in sixth place had they beaten Halifax last week, but after an encouraging start the Yorkshire side wrested control of the game away from their opponents.
“It was the best we’ve started for a long time against Halifax and it was just a little patch where we conceded seven back-to-back penalties which they scored two tries off,” Pickersgill continued.
“If it wasn’t for that spell in the game then I reckon we could have come away with a win.”
Batley and Sheffield could each move towards cementing a play-off spot should they win this weekend; the Bulldogs are at home to table-topping Featherstone while the Eagles will host Halifax.