Northampton Saints captain George Furbank is out of Saturday's Investec Champions Cup semi-final against Leinster.
The England full-back marked his return from the broken arm he suffered in December with a try as Saints powered past Castres 51-16 in the quarter-final.
But Furbank is still feeling the effects of having metal plates inserted into his arm and will miss this weekend's blockbuster in Dublin.
"George won't play this weekend," said director of rugby Phil Dowson.
"He's struggling to get over that arm break and getting back into contact is hard for him. He keeps getting whacked and it's going numb and it's very painful.
"I don't think that's unusual for an arm that's been plated. He's clearly desperate to get back in, particularly for a game like this, but unfortunately it's too soon."
Dowson was unable to say whether Furbank will play a part again this season, or if he would be available should the Lions come calling this summer.
"It's week by week really." added Dowson. "He's not a soft lad but it's clearly very painful, and worst-case we don't want to make it any worse.
"We're trying to manage that conservatively with the stresses of time running out as well.
"I think it's very variable but my impression is it takes a while to get back into it. There's not a huge amount of meat around that part of the body if you're swinging it around and landing on it in a tackle or other people are landing on it.
"I couldn't tell you what's going to happen. I've asked the physio about 485 times if he can play and the physio has said no every time. I'll ask again next week."
Saturday's showdown is a repeat of last season's semi-final, which Leinster won 20-17.
Saints have almost no chance of making the Premiership play-offs in defence of their title, so the Champions Cup is realistically their last chance of silverware this season.
PA
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