"We are under pressure from Pakistan's performance; when you're dropping good players, you're giving them two chances at bat," he said. "There's no excuse, there are no 38-year-olds [in the Bangladesh team] running out there. They are all in their mid-twenties. Young men should be fighting fit for four to five days.
"That is an area of concern for us. I think our bowlers did well and created enough opportunities. It's not a practice thing. We practice till hands are sore."
On the fourth day, Bangladesh put down three catches - Robiul Islam shelled a simple chance at mid-on, Mahmudullah dropped another at slip and Sunny one at midwicket - as Pakistan went on to take a lead of 132 and then knock over five Bangladesh wickets with the hosts still in the deficit.
However, Law has confidence that Bangladesh can still draw the game. "If the two at the crease [Mushfiqur Rahim and Nasir Hossain] can bat, we can [secure a draw]. If we can bat 2-2.5 sessions, I believe we can."
Bangladesh had lost wickets in a hurry, after making up a commendable 338 in the first innings, with some of their batsmen - Mahmudullah in particular - playing questionable strokes. That shot, Law said, stemmed from the fact that Bangladesh play more one-day cricket.
"I've spoken to him [Mahmudullah] about that. It comes from being a one-day cricketer. We don't play a lot of Tests. It's okay if you play that shot when you chase eight or nine an over but in a Test match, when you're looking to save the Test, it's not the right option. We need to play more of long format of the game, as a team."
Bangladesh were set back by a double-strike from Umar Gul that accounted for Tamim Iqbal and Shahriar Nafees on the stroke of tea. Both batsmen, though, received rough umpiring decisions in a series where the DRS isn't available.
"They [the umpires] have the most difficult out there," Law said. "It's not the decisions, but the timings of them. Just before tea to lose two wickets in two balls to decisions that we felt were quite questionable. It's a massive kick in the guts.
"It's just a great reminder to everybody that this DRS is something that as a team [we could use]. A lot of talk about us fighting for survival in the international scene. If decisions don't go our way, and there seem to be quite a few, it makes our job that much more difficult."
Pakistan batsman Mohammad Hafeez said his bowlers had put the team in a fine position. "Our bowlers have worked very hard and have taken five wickets today. The new ball was doing a bit. We are in a position where we can put pressure on the Bangladesh batsmen and we are very much on track [to win the Test]."
Hafeez also appreciated Shakib Al Hasan's effort - the allrounder followed up his century with six-wicket haul. "Shakib's performance was great. I think he was under some pressure for not scoring in the ODIs. He came out with a strategy and executed it well.
"He bowled really well after scoring the hundred, which is something special. He is doing a wonderful job for Bangladesh."