Buffalo also acquired minor-league forward Mike Sislo in the deal Thursday.
Hickey joins three former Boston University teammates on Buffalo's roster, including star center Jack Eichel. Hickey was the Terriers' captain in completing his senior season, and finished his career with 21 goals and 54 points in 147 games.
Fasching spent a majority of his two-plus seasons with Buffalo in Rochester, the Sabres' American Hockey League affiliate. The 22-year-old had a goal and two assists in 22 career NHL games.
Arizona later acquired forward Adam Helewka from the San Jose Sharks in exchange for defenseman Kyle Wood.
The 22-year-old Helewka had nine goals and 29 assists in 63 games last season for the San Jose Barracuda in the AHL. Wood, also 22, had three goals and 16 assists in 49 games last season for the Tucson Roadrunnersin the AHL.
The Sabres also signed prospect goalie Ukko-Pekka Luukkonen to a three-year, entry level contract.
Luukkonen is from Finland and was Buffalo's second-round pick in last year's draft. Luukkonen entered the draft listed first among European goaltenders in the NHL Central Scouting rankings after leading HPK to win Finland's Junior Hockey League championship.
This past season, the 19-year-old had an 11-11-2 record and 0.909 save percentage playing professionally with Finland's second-division LeKi Lempaala.
The Sabres have organizational depth needs at goaltending with Linus Ullmark projected to make the jump to the NHL after spending the past three seasons developing in the minors.
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