MANAGER Kenny Jackett admitted Millwall were not at their best during their 1-0 win over Preston North End in the third round of the FA Cup.
The Lions ground out a narrow victory over the League One side courtesy of Liam Feeney's first-half goal and a resilient defensive performance after the break.
Jackett said: "In the first-half we played very well and had two chances at the start of the second-half plus a three-on-two situation where we needed to be further ahead.
"We came out of that period and had to defend for the final 35 minutes of the game. To some degree, that's frustrating for me as the manager.
"The quality of our breaks and passes out of defence wasn't necessarily great. We had to put in a real defensive shift – we did that and we came through it.
"Preston had a number of corners and their 4-3-3 formation gave us a few problems. David Amoo coming back to his old club was also a handful.
"The quality of our play in the second-half can be better. But if you have to defend, so be it. We're through to the fourth round and we're very pleased."
Feeney's involvement was cut-short by injury and the winger was forced off at half-time. Jackett said: "It's a shame that he had to come off with a hamstring problem.
"He's gradually improved playing on the left wing. He's made good substitute appearances against Brighton and Cardiff recently and I was very pleased with those.
"He's getting to grips with running with the ball and getting into games, mostly checking back onto his right foot but delivering some good crosses as well.
"He's getting used to the position and it's a frustration that he may have to come out of the side now. The early signs are that it's not too bad.
"But hamstring injuries are generally two or three weeks. My experience tells me he may need a break, but perhaps I'll be surprised with some good news during the week."
The Lions were without Liam Trotter and Danny Shittu for the visit of the Lillywhites, with Jackett confirming both players had slight knocks.
He said: "Trotter had a back injury after the game on Tuesday and Shittu had a problem just above the knee – a dead leg really. I'm hopeful both will be okay for next weekend."