MILLWALL will be sweating on the fitness of defender Jack Smith ahead of their trip to Peterborough in midweek.
Smith limped off with a thigh strain midway through the second period of the Lions' 2-0 defeat to Blackpool and is now a doubt for the match at London Road in 72 hours' time.
"Jack's thigh was very tight," Jackett said.
"It's a muscle injury so whether that will impact on my plans for Peterborough on Tuesday we'll have to see. But his thigh was tight rather than pulled.
"It's been the nature of our pre-season so far. Having said that, we have some experienced players to come back in terms of playing in the division and at the club.
"We haven't been short in those terms in any of the six defenders I used against Blackpool.
"Our solidness and distribution from the back needs to improve but we're not necessarily going to sign any more defenders. I don't think that's the case."
Jackett also confirmed that neither Paul Robinson or Tamika Mkandawire will feature against Peterborough nor at Sheffield Wednesday next Saturday.