Striker Shane Long is out of the Republic of Ireland's crucial World Cup qualifier in Russia.
The West Brom frontman, who missed last night's disappointing 0-0 draw with Slovakia after suffering a calf strain, was today ruled out of the clash with the Group B leaders at the Luzhniki Stadium on Tuesday.
However, skipper Robbie Keane, who received a knock to the back, and defender John O'Shea, who has a sore Achilles tendon, are expected to be fit.
Trapattoni will have to make at least one change with central defender Sean St Ledger suspended after picking up a second booking against the Slovakians.
Darren O'Dea could replace him, although O'Shea could move inside with either Kevin Foley or Stephen Kelly taking over at right-back.
Russia are two points clear at the top of the group after their 1-0 win over Macedonia with the Republic and Slovakia level in second on 14 points