The Warriors coach describes their 19-9 defeat by Glasgow Rugby in the first round of the Celtic Cup back in September as a bad day at the office for everyone and, having lost to them in that game, that puts an extra edge on this match.
We will have to be more physical on Friday because in the cup they outmuscled us and our ball retention and turnovers were the worst by any side I have been involved with - basically we did not turn up.
It makes this a big, big game for us, particularly in light of us losing by a point at Munster. We dominated up front, had the far better set pieces and broke them behind.
However, we ended up with an 18-7 penalty count against us and it is the type of result you have to put firmly behind you if you don't want to get too morose.
The Warriors now have 19 squad members not available for selection for a variety of reasons, centre Jon Bryant tearing a calf muscle in the warm-up at Thomond Park.
Jon will be out for about three weeks, though Leigh Thomas from our academy came in against Munster and did really well, said Howells.
Dafydd James had a run-out with Bridgend last week but we did not want to risk him last weekend as his shoulder is still tender and we will see what the reports on him are like during the week.
However, Maama Molitika did get in 20 minutes against Munster and having him back in the selection mix is a big bonus.
Celtic League - Friday 7th November.
Cardiff Blues v Gwent DragonsVenue: Arms ParkKick-off: 7.05 Referee: Gregg Davies (S)TV: BBCW
Celtic Warriors v Glasgow RugbyVenue: Brewery FieldKick-off: 7.15Referee: Tony Redmond (I)
The Borders v N-S OspreysVenue: NetherdaleKick-off: 7.30Referee: Simon McDowell (I)
Edinburgh Rugby v Munster
Leinster Lions v Llanelli ScarletsVenue: DonnybrookKick-off: 7.35Referee: Rob Dickson (S)TV: TG4
Celtic League - Saturday 8th November
Connacht v UlsterVenue: SportsgroundKick-off: 2.30Referee: Phil Fear (W)
Leinster: Gordan D'Arcy; John McWeeney, Christian Warner, David Quinlan, Gary Brown; Matthew Leek, Brian O'Meara; Emmett Byrne, Gavin Hickie, Niall Treston; Aidan Kearney, Ben Gissing; Niall Breslin, Shane Jennings capt> Des Dillon.Replacements: Peter Coyle, David Blaney, Ciaran Potts, Niall Ronan, Shane Whelan, Peter McKenna, Daragh O'Shea.
Connacht: Mark McHugh; Matt Mostyn, Darren Yapp, Tim Allnutt, Conor McPhillips; Eric Elwood, Mick Walls; Rory Hogan, Bernard Jackman, Adrian Clarke; Matt McCarthy, Andy Farley; Michael Swift, Paul Neville, John O'Sullivan.Replacements: John Fogarty, Fabien Boiroux, Damien Browne, Tom Carter, Conor O'Loughlin, Dave Hewitt, Wayne Munn.
Munster: Dominic Crotty; Martin McPhail,Mike Mullins, Conrad O'Sullivan, Mossie Lawler; Jason Holland,Eoin Reddan; Simon Kerr, Andy Long, Frank Roche; Trevor Hogan, Stephen Keogh; Denis Leamy, Colm McMahon, Jim Williams cap. Replacements: Eugene McGovern, James Blaney, Donal Sheehan, Tom Hayes, Frank Murphy, Keith Matthews, Clem Casey.
Ulster:Bryn Cunningham; James Topping, Ryan Constable, Shane Stewart, Scott Young; Adam Larkin, Kieran Campbell; Bryan Young, Matt Sexton, Rod Moore; Matt Mustchin, Matt McCullough; Andy Ward capt, Neil Best, Tony McWhirter.Replacemnents: Paul Shields, Ronan McCormack, Rowan Frost, Roger Wilson, Reece Spee, Paul Steinmetz, Seamus Mallon