The 6-foot, 180-pound Carswell signed with Alabama in 2010, when he was rated as a top 75 receiver by the major recruiting services, but was suspended late in the 2011 season. He played last season at Itawamba (Miss.) Community College and caught 44 passes for 429 yards and one touchdown in nine games.
Underwood played the past season at Copiah-Lincoln (Miss.) Community College, where he was first-team All-NJCAA Region 23 and first-team All-Mississippi Association of Community/Junior Colleges. Underwood played as a freshman at Southeast Louisiana in 2011.
He's expected to battle with senior Pat Eger for the team's starting center position. Eger has started games at tackle and guard in his career, but only started playing center in the spring. He missed the end of spring practice, including the spring game, with an ankle injury.
Carswell has two years left to play two seasons while Underwood has three years left to play two seasons.
The 6-3, 185-pound Trickett played two seasons in three years at Florida State. Since he graduated earlier this month, he was permitted by the NCAA to transfer without having to sit out a season. The son of Seminoles and former WVU offensive line coach Rick Trickett, he has two years left to play two seasons.
He'll compete against junior Paul Millard and redshirt freshman Ford Childress for the starting spot, but Trickett will hold an edge in experience. He played in 17 games with two starts at Florida State, including a win against then-No. 21 Clemson in 2011, the year the Tigers won the ACC before losing to WVU in the Orange Bowl.
Trickett left Florida State with modest statistics, though. He completed 66 of 106 passes for 947 yards, seven touchdowns and four interceptions.
McCartney seemed to be on his way as a sophomore in the first half of the 2011 season, when he caught 34 passes for 455 yards and three touchdowns in the first six games. He had just 15 receptions for 130 yards in the final seven games and just nine catches for 112 yards in eight games in 2012. The 6-2, 185-pound McCartney left the team in November.
McCartney, a fourth-year senior, will again be on scholarship, but he won't count as a new recruit against the numbers in the 2013 class. The Mountaineers can still sign one more player to count toward that group.
Contact sportswriter Mike Casazza at mi...@dailymail.com or 304-319-1142. His blog is at blogs.dailymail.com/wvu.