Director of Cricket Steve Rhodes was disappointed Worcestershire were unable to put the finishing touches to a "fantastic effort" after recovering from being on the receiving end of Sussex batsman Matt Machan's first day onslaught at Hove.
The county fought back from Machan's 70 ball 100 to bowl their opponents out twice and gain a first innings lead of 44 only to be dismissed for 185 today and go down by 61 runs.
Rhodes told BBC Hereford-Worcester's Dave Bradley: "I thought after they were 150-1 for lunch on the first day, to get ourselves in a position where we could win the match today was a fantastic effort by the team.
"But sadly we failed to carry that out today so that was a disappointment.
"I think at 57-0, we were going really well chasing that score (247), and then we were 60-3 with two decisions our best two players have experienced in Daryl Mitchell and Alex Gidman. But I'm not allowed to talk about lbws, so I won't comment on it.
"They got back in the game today and that hurt us. It is something we are going to have to address because we lost quite a clutter of wickets today and we can't afford to do that.
"They are a young experienced side that are learning all the time but those are the sort of experiences that take a bit of time to get over and learn from but it's something we will definitely have to address.
"We've been very competitive in the two games but when you are playing tough cricket, you are waiting for opportunities to arrive and then you take them and that's sadly what we haven't done."
Sussex skipper Ed Joyce said: "Worcestershire fought really hard and you have to give them credit. It was an excellent game on a really good cricket wicket."