MINNEAPOLIS, Feb. 7 (UPI) -- Minnesota Vikings running back Adrian Peterson, coming off an NFL-best rushing season, underwent sports hernia surgery, the team said Thursday.
The Vikings said they expect a quick recovery and no long-term issues for Peterson from the abdominal core muscle injury repair.
Peterson had surgery to repair knee injuries in December 2011 and went on in 2012 to a near-record 2,097 yards rushing with 12 touchdowns.
For his career, Peterson has rushed for a Vikings record 8,849 yards with 76 touchdowns. He's also has caught 177 passes for 1,526 yards and four more scores.
NFL bounty coach Gregg Williams reinstated
NASHVILLE, Feb. 7 (UPI) -- Gregg Williams, suspended after being implicated in the New Orleans Saints injury bounty program, was reinstated by the NFL and joined the Tennessee Titans.
A statement by the NFL Thursday said Williams would be allowed back into the league and that Commissioner Roger Goodell had approved a contract Williams signed with the Titans as a defensive senior assistant.
"The commissioner cited several reasons for the reinstatement, including Williams' forthcoming acknowledgement of and acceptance of responsibility for his role in the bounty program at the Saints, his commitment to never again be involved in a pay-for-performance or bounty system and his pledge to teach safe play and respect for the rules at all levels of the game," the NFL statement read.
"The commissioner emphasized that Williams must fully conform to league rules and will be subject to periodic monitoring to confirm his compliance."
Williams was suspended indefinitely last March by Goodell after an internal investigation indicated Williams, as the Saints' defensive coordinator, ran a bounty program that allegedly paid players for injuring opponents.
New Orleans Coach Sean Payton recently was reinstated by Goodell after nearly a year away from the team. Other team officials and players were also suspended.
The NFL claimed that Williams was responsible to a program in which Saints players contributed money, with cash paid for good defensive players, including interceptions but also for causing injuries to opposing players.
Croat Cilic advances in Zagreb
ZAGREB, Croatia, Feb. 7 (UPI) -- Home-country favorite Marin Cilic beat Grega Zemlja in straight sets Thursday in second-round play of the PBZ Zagreb Indoors tennis tournament in Croatia.
Cilic, the top seed for the tournament, has won four of his eight ATP championships in Croatia, including taking the Zagreb event in 2009 and '10. He advanced to this year's quarterfinals with a 6-2, 6-3 decision over Zemlja.
Cilic had 11 aces and didn't drop his serve, winning three-quarters of the points when serving. He finished off three of his four break opportunities.
Ivan Dodig edged by Ivo Karlovic 7-6 (7-2), 6-7 (2-7), 6-3 in an all-Croatian match. Dodig managed just two break changes against the hard-serving Karlovic, including a break at love in the sixth game of the third set.
The tournament lost three seeded players, including No. 2 Andreas Seppi, who withdrew before Thursday's play. Robin Haase knocked off fifth-seeded Martin Klizan 6-2, 4-6, 6-4 and Blaz Kavcic ousted No. 6-seeded Marcos Baghdatis 3-6, 7-6 (7-2), 6-4 in second-round upsets.
Fourth-seeded Jurgen Melzer gained the quarterfinals with a 1-6, 7-6 (7-5), 6-2 win over Somdev Devvarman while Lukas Rosol got by Flavio Cipolla 6-4, 2-6, 6-3 and Philipp Petzschner beat Dino Marcan, inserted in Seppi's slot in the draw, 6-3, 6-4.
Cilic faces Kavcic and No. 3-seeded Mikhail Youzhny goes against Dodig in the draw's top-half quarterfinals. The other matches Friday have Melzer playing Rosol and Haase meeting Petzschner.
Kieffer, Sterns tie for Joburg Open lead
JOHANNESBURG, South Africa, Feb. 7 (UPI) -- Maximilian Kieffer and Richard Sterne shot 8-under-par 63 Thursday and are tied for the lead after one round of the European Tour's Joburg Open in South Africa.
Neither co-leader had a bogey Thursday while playing the West Course of the Royal Johannesburg and Kensington Golf Club. They move to the East Course for their remaining rounds.
The tournament is contested on the East and West courses until after the second-round when the rest of the event is on the par-72 East Course.
Bryce Easton had a hole-on-one on the 200-yard 12th hole in turning in a 7-under 65 for the best score of the day on the East Course. He had a birdie on the sixth hole and finished each nine with back-to-back birdies.
Eight players are tied for fourth at 6-under.
Sterne opened his round with three straight birdies and added a birdie at the par-3 eighth before chipping in for eagle at the par-5 ninth hole. He got to 8-under with birdies at 13 and 15.
Kieffer had four sets of back-to-back birdies. His first came at Nos. 2 and 3 with another at 6 and 7. He made the turn at 5-under after a birdie at the ninth hole and opened his second nine with a birdie at 10. He tied Sterne with birdies at 15 and 16.