Aberdeen: Goalkeeper Tomas Cerny and defender Tommie Hoban join Dons
Watford's Tommie Hoban is determined to use his season-long loan spell at Aberdeen to "kick-start" his career.
The former Republic of Ireland Under-21 defender, 24, has played 54 Championship games for his parent club.
Hoban will go straight into the Dons squad for Thursday's Europa League first-leg tie with Burnley, pending the receipt of his international clearance.
"The last three years have been difficult with injuries, I've had a bit of bad luck," Hoban told RedTV.
"I'm over that now, I'm feeling fit and hoping this is the start again, that this is going to kick-start my career. To be at a big club like Aberdeen it's the perfect place to do that."
Watford say they hold an option to recall Hoban in January.
Aberdeen boss Derek McInnes, who has also signed goalkeeper Tomas Cerny, hailed the versatile defender's arrival as a "great piece of business".
"First and foremost he's an excellent defender," the Pittodrie manager said. "It's well known that we've been in the market for another defender and to get a player of his quality from Watford is a great piece of business.
"Although he can play anywhere in the defence, centre-back is his preferred position."
Meanwhile, experienced goalkeeper Cerny has joined the Dons on a one-year deal.
The Czech, 33, left Partick Thistle following their relegation to the Championship last season, and will also be eligible for the visit of Burnley.
His arrival affords McInnes a seasoned back-up to Lewis after letting Danny Rogers gain top-flight exposure on loan at St Mirren.
"When we made the decision to allow Danny Rogers to go out on loan, we had been looking at potential options to provide cover for Joe Lewis and the injury to young David Craddock at Inverurie on Monday evening accelerated that process," the Dons boss said.
"We're delighted to bring in a player with such experience and who was so willing to get the deal done. Having Tomas as cover will allow Danny to gain valuable match experience at St Mirren."